Please check out the Dash lights went out but fuses are good forum....we need help if possible...thanx in advance.

 

I saw the thread but did not respond because I don't know the answer. Sorry...

 

Do the brake lights work normally?

Does the symptom change when you step on the brake?

Does the ash tray light work?

Does the glove box light work?

 

The brake lights work fine

The symptom does not seem to change when stepping on the brakes

The ash tray was the last light to go out, does not work now

The glove box does work

Thanx

 

Please check fuse #18 (7.5 amps) and fuse #13 (10 amps).

Your symptoms could be caused by a bad dimmer or a bad ground connection to the dimmer. The dimmer has three terminals and number 3 (black wire) goes to ground. You could remove the dimmer and check ...
- terminal 1 (blue/yellow) should have +12 volts if the park lights or headlights are on.
- terminal 3 (black) should have continuity to ground.

If you get the expected measurements, you could fashion a special-purpose jumper to use as a temporary substitute for the dimmer. It would short together terminals 1, 2, and ground. If that gets you full-bright instrument lighting, then the dimmer is bad. If not, the problem is elsewhere. There is a diode in the Combination Meter printed circuit board. That diode might be "fried".

 

Hi Dan,
If the dimmer is faulty, wouldn't it affect all lighting under its control? This problem is just a subset. I turned the dimmer control up and down to verify.

I'm thinking your point about the Combination Meter may be the case... I had one unusual side effect in this whole thing--when I reconnected my Bose head unit (I had taken it apart to investigate the unlit display problem), I ended up getting a rapid clicking sound coming from behind the dashboard (a relay is my guess). It caused the security light to flicker quickly, too. I removed the Bose head unit, and it stopped. I took apart the Bose unit again, just to make sure I didn't accidentally create a short somewhere, then carefully put it back together and plugged it in again. The rapid relay clicking started again, and this time the security light stopped flashing (it still works in normal use, though). The only time the relay clicking would stop with the Bose unit in place, was when I'd put the ignition switch on to Accessory or Ignition positions.

It was a day or two after this incident when I first noticed I didn't have illumination on the climate controls. Do you agree--fried Combination Meter? If so, how hard is it to fix this? I have some soldering experience, but... perhaps I'm better off replacing the circuit board?

Thanks for lending an ear in this!

 

Yes, but reading the original thread made me think several people are reporting similar but not identical problems.

AFAIK there is no relay on the back of the Combination Meter, or behind it. I don't know what might have made that clicking sound. Diodes "die" silently. If you have experience reworking printed circuit boards you could certainly replace a bad surface-mounted diode.

Removing the Combination Meter is covered in the Chilton repair manual (page 6-15) and the Haynes repair manual (page 12-9).

 

Yep, the symptoms are similar but explained slightly differently by some. Dmbrazilian has the same situation as I do, except he said it happened one thing after the other. Mine was all at once. Such is the nastiness of electrically related problems (I won't even begin to tell of my "ghost" electrical problems in an old Datsun 2000 I once had).

I was just thinking the rapid clicking sounded like a relay, and that it was indicative of something amiss electrically (caused by the faulty head unit) that eventually burned out the diode.

Anyway, I'll take a look in the manuals on this. I'm not skilled enough to troubleshoot the board (and then hunting down the right diode would be a pain in itself). But I'll have to find a way to determine if this is the actual problem. Is the Combination Meter part expensive to replace?

 

There are only three diodes on the board. You could unsolder one at a time, and unit test them. Diodes are inexpensive; you could unsolder and replace all three. However, I'm not confident the problem is a bad diode. We don't know what made that clicking sound, so making a mental connection between an unknown sound and a presumed dead diode is a long reach.

"Weird electrical problem" always makes me think "bad ground somewhere". I hope you will devote more time to diagnosis before removing the Combination Meter. That's a non-trivial job.

This question should be answered by your dealer parts man. I think it is several hundred dollars. To make matters worse, a new Combination Meter includes a new odometer and then you run into the hassle of getting the dealer to synchronize old and new odometer readings or else acquire the True Mileage Unknown stigma on your title.

 

... thanks, Daniel, for your participation in this topic. I ran checkouts on my '96 GLE as suggested and, although I haven't solved the problem, wanted to add to the database.

- brake/tail lights all work normally;
- symptom does not change with application of brakes;
- ashtray light does work with use of headlight switch;
- glove box light does work " " " " ";
- all fuses check okay, including #18 and #13;
- black wire (to dimmer) checks okay to ground;
- red/yellow and blue/yellow wires both go to 12 volts with use of headlight switch, regardless of dimmer setting, whether brakes in use or not, ign key switch on or not, and whether or not the dimmer is connected to the harness;
- did try a new dimmer, nothing changed/improved;
- appears that all illumination controlled by the dimmer is out, digital displays in climate control and (Bose) stereo work fine until headlights come on, then they go dark. Digital clock does dim per normal for night driving;
- everything affected all at once (like Gary95), no DIY stuff going on beforehand (unlike Gary95 and dmbrazilian);
- no relay noises, etc. noted;
- have not pulled instrument cluster yet to check the diodes. When I get to that, I expect I'll try to check them while still in the board. Any thoughts on that?

Daniel, you made reference in another thread...
http://forums.maxima.org/showthread.php?threadid=32908
... of a Body Control Module. Does this unit have a role in this situation? I found the fuse identified as BCM (in the engine bay fuse box), it checks out okay. For lack anything better to do, I call several Nissan Parts Depts. to identify and price the BCM. At 3 separate dealers, the parts man could not find a part identified this way, but did come back with items known as LAN Module and/or Control Assembly. Hope we're not talking about one of these, prices out to be $812!

 

well, i read this post and i saw you talking about your head unit and that some lights werent lighting up right... well the other day i noticed that on my aiwa cd player some of the buttons (like the whole left side) wont light up... mayeb you have some idea as to why? i will try and clean the contacts from the face to the unit (removable face-plate) .. think that will work? but all the sudden? hmm...

 

Since the job of a diode is to let electricity flow in one way, would it be possible to just procure another diode of the same rating and touch the leads in parrallel with each of the suspected bad diodes and see what happens?

if there are no relays present in that area, it could be that the popping noises you were hearing was electrical arcing. You might be able to 'smell' the area for burnt smells as well as look for small black burn marks...

-V

 

This is a good idea, as it prevents unsoldering a good diode just to test it.

 

The electrical noise I heard was definitely a precise and regular "click" sound, like that of a relay (e.g. when you engage the turn signal or hazards). Only it was rapid. So I'm not convinced it was electrical arcing. Didn't have that characteristic scratchy "pop" sound, and no smell either.

I agree with your diode test--sounds like a simple and effective way to troubleshoot that part of it. I'm also planning to pull out my trusty-dusty volt meter to see if I can trace the current back to where it should be coming from. That'll be a loooong day, for sure--kind of dreading it. The only thing more frustrating than trying to hunt down the paths of twisty hidden wiring is to remove a seriously rusted bolt with minimal access.

 

You have done a lot of good diagnostic work. This is a stubborn problem. I offer these thoughts in a suggested sequence.

1) A bad ground connection can be ticky to recognize. Please run a test lead from dimmer terminal 3 to the negative battery terminal. See if the symptom persists with this test lead in place.

2) Remove the Combination Meter.
Remove the front cover from the CM housing.
Open the connector cover.
Release the connector lock by holding both ends of it and pulling it up.
Disconnect the Flexible Printed Circuit (ribbon cable) by pulling it up.
Carefully clean the connector and the end of the FPC with a suitable liquid cleaner. Caig Laboratories DeoxIT is the one on my bench, but there are similar products. http://www.caig.com/
Insert the FPC into the connector.
Lock the connector by pushing downward.
See if the symptom persists.

3) Explore the possibility of a failed diode on the CM printed circuit board.

 

You have done a lot of good diagnostic work. This is a stubborn problem. I offer these thoughts in a suggested sequence.

1) A bad ground connection can be tricky to recognize. Please run a test lead from dimmer terminal 3 to the negative battery terminal. See if the symptom persists with this test lead in place.

2) Remove the Combination Meter.
Remove the front cover from the CM housing.
Open the connector cover.
Release the connector lock by holding both ends of it and pulling it up.
Disconnect the Flexible Printed Circuit (ribbon cable) by pulling it up.
Carefully clean the connector and the end of the FPC with a suitable liquid cleaner. Caig Laboratories DeoxIT is the one on my bench, but there are similar products. http://www.caig.com/
Insert the FPC into the connector.
Lock the connector by pushing downward.
See if the symptom persists.

3) Explore the possibility of a failed diode on the CM printed circuit board.

 

Hi Dan - you've mentioned the bad ground connection possibility a couple of times. What usually causes this? The only wiring I ever touched was connected to the DIN plugs for the climate control, hazards, rear defroster, stereo and ash tray. Simply unplugging them and reinserting them later. The DIN plugs were on very tightly, taking extra effort to get them off the pins. But I was careful not to break anything or fray a wire. I examined them yesterday, and all wires seem to be properly seated.

In my case, if my dimmer control affects the lights that are still getting power, is it safe to say that the dimmer couldn't be at fault with this subset of lights not working?

 

I'm with you on that one Gary, my dimmer is also doing its job on the lights that still work...I wish I had more time on my hands to also get out there and do some examining.

David

 

Yes. I'd also think the diode in the instrument cluster is good. The problem in your car is probably physically close to the lights which aren't working. Broken wire, loose connection, etc.

Bad grounds are unusual, and the problems they cause are unusual. I'll answer your question about the cause of bad grounds in a general sense, not specifically addressing the lighting problem central to this thread. Bad grounds may arise from ...

Collision damage.
The car was in a crash. The unibody was distorted. Harnesses were stretched. Sharp pieces of metal or glass cut through plastic insulation. The bodyshop tends to focus primarily on sheet metal and paint. They may have overlooked (or never checked for) wiring damage. This damage does not always show up right away.

Corrosion damage
The car is used near a body of salt water. The car is used in the rust belt where heavy applications of salt are needed during severe winters. At some point the battery case was cracked (crash damage?) and the acid leaked out. The battery was replaced but corrosion done by the acid was overlooked.

Mechanical damage
Some factory electrical connections are made with crimped splices. These splices are often concealed under the black plastic protective wrapping which surrounds most harnesses. Some harnesses are routinely flexed during normal vehicle operation. Harnesses which lead from the body to the powertrain are especially vulnerable to this flexing which may loosen a splice or break a wire inside an intact insulator. Harnesses which lead from the body to a door are also subject to this kind of damage (mysterious power window misbehavior).

 

Sorry to chime in again... but did you end up with any 'extra' screws as a bonus when you put everything back together?

I think I MAY have a theory as to what's going on here.

If a stereo was installed, when you put everything back together, a screw was missed. This would cause a bad ground, or no ground at all for a specific piece of hardware. Either that or the attachment ground point of all the electrical devices in that area has worn or broken. It's usually like a wire going to a bolt that bolts to a metallic area.

With such a bad ground, current will still try to find a way back to the battery, even though it may not be the most efficient. One way is through the antenna connector on the back of the stereo as the antenna shielding is grounded to the body. Another may be through the casing of a unit.

Now here's the long shot... the head unit shares a ground wire with the lighting and other devices in that area. That ground could be bad. So that when the head unit was plugged back in, the antenna or ground of the chassis of the headunit became the ground. It's still getting it's positive from some other device that's ground. Because the current was flowing in reverse, it could've been triggering the relays for the stereo (i noticed my bose causes a click near the glove box/center consol area everytime i turn i to on and off) or some other relay. When you turned the key to the acc positision, another device that shares a common ground point with everthing else might have a small ground wire terminating at a different point, which is not the path of lease resistance, so the current stops trying to flow through the artificial ground created by the headunit...

I don't have an FSM, but in the electrical diagrams, there should be a upside down triangle made up of several horizontal lines. I bet you the whole center area shares a single ground, and that could be the source..

Also try putting the DMM/multimeter into ohm/resistance mode and try touching one side to a known good ground or wire leading to the negative terminal of the battery. Then touch the other side to some metal areas in the center console area behind the plastic trim pieces and see if you're getting ground...

-V

this may be just a load of crap so don't kill me if i'm not making sense or what i'm seeing seems like non-sense

 

vmok, I think you may have it. I did not reinstall my head unit at all. I simply connected it to the DIN plugs without it being mounted in the metal brackets. If there is a shared ground, then... that may explain it all!

In the case with these other guys, if they haven't ensured that the common ground is properly completed with the new head unit, that would also explain why some of their lights aren't working.

Very strange design, IMHO. I would think the stereo head unit should have its own separate ground. But who knows... Nissan does cut corners here and there to save $$.

I'll let you know when I try it out. Thanks for the advice!

 

I just received my new headunit, so I'm ready to install it and see if the full installation corrects the problem. But unfortunately, I can't get to it until next weekend.

Has anyone figured out the problem yet?

 

Well I got mine fixed guys....all it its is the bulbs !!!!!!!!!!they go bad after a while sometimes. Well I went to nissan and ordered some new ones put them in and thats all it was....maybe you guys should try it as well...

David



I just received my new headunit, so I'm ready to install it and see if the full installation corrects the problem. But unfortunately, I can't get to it until next weekend.

Has anyone figured out the problem yet? [/QUOTE]

 

The bulbs? Are you sure? That seems REALLY strange they'd all go at once. Especially being LEDs. Unless... perhaps there was some kind of voltage spike that fried them all. But it's so strange how it would be isolated to a nice neat grouping like that.

Did you have your rear defroster bulb replaced as well? If not, then I'm thinking there's some kind of serial issue going on, where one bulb fails and they all fail.

 

Well there are 4 bulbs for the ac unit, and two bulbs for the defrost, all of the ac unit bulbs were out got some new ones and they are fine now. As for the defrost they don't sell just the bulbs, only the illumination bulb was out on the buttom, they wanted about 25 or 30 bucks for the whole unit, so I went to radio shack and bought some little project type bulbs that were the same as the ones one the defrost and put them in there....works fine and it cost me 1.50 for two bulbs. I also had to get a bulb for my ash tray light which was like 7 bucks I think at Nissan.....everything works now....I should have checked the bulbs a long time ago before going through all this head ache...I suggest that all of you check those bulbs as well, the dealership said that they go out after a while.

 

I had posted before that installing a new dimmer switch did not solve my dash lighting problem. Before tearing into the electrical system any further, I bought a HAYNES repair manual for 93 thru 99 Maxima and studied the wiring schematics. I gotta tell you, the dash lighting system is pretty straightforward. I refused to believe that ALL of the bulbs controlled by the dimmer switch had burned out simultaneously, not to mention loss of stereo and climate control fluorescent displays with headlights on (no offense intended dmbrazilian, sounds like your situation was different), and measurements I made confirmed that. So...

... I bench-tested my original dimmer switch and it really was bad. The way it's supposed to work is: the "low" side of all the (dimmable) bulbs are ganged together and connected to the middle terminal (red/yellow wire) on the dimmer. When you turn on the headlamp switch, 12 volts gets applied to the "high" side of all of the (dimmable) bulbs AND an exitation terminal (blue/yellow wire) on the dimmer at the same time. As you adjust the dimmer it modulates the voltage available to the "low" side of the bulbs between 12 volts and ground (black wire), thereby changing the apparent brightness of the bulbs. My dimmer did NOT modulate the center terminal (stayed at 12 volts regardless of thumbwheel position), so I took my dimmer apart, and this thing is pretty wild. There's a small printed circuit board inside with digital circuitry which processes instructions to a current carrying high speed MOSFET switch. The board is labeled T1 where it's located and, with a low power iron and a "solder-sucker", it came out pretty easy. The transistor is an International Rectifier P/N IRLZ34, on the street, the cross-reference is NTE2985, I bought a few for $2.32/ea. I reassembled the dimmer with a new MOSFET soldered into the board, and voila, it worked!

So far, everything in the car is back to normal. I can't explain why the thing failed in the first place, and the new one I bought from Nissan (which, out of the bag, did not work, at all, ever) now works perfectly after replacing it's MOSFET as well. I won't be able to return the new one, being special ordered and electronic parts, yada yada yada. Anybody interested? Nissan part number is 25980-70F00, cost 75.13 plus tax, which in CA, was $80.76 out the door. I don't expect to recoup all of that, but let's make a deal.

If one has the wherewithal, you can run the basic checks on your dimmer in the car, and I recommend you do so before tearing into other areas of the system. Make sure that Fuse 18 (7.5 Amp) is good and that you get 12 volts at both ends of this fuse (with respect to ground) with the headlight switch on (parking lamp position is okay) and 0 volts with the headlight switch off. If this checks out, you need access to the rear of the dimmer where the electrical connector is, so it has to come out of the instrument cluster bezel. HAYNES says to pry it out from the front using a flat blade screwdriver, wrapped in tape to avoid scratches. I, however, ending up removing the bezel altogether to gain direct access the one-way dogs on the sides of the dimmer because they were very stubborn and it felt like I'd end up breaking something otherwise. The procedure for removing the bezel exists elsewhere in this forum. HAYNES also cautions that, when working on the electrical system, especially in and around the steering wheel, that the airbag system should be disabled. If this sucker gets triggered, it could hurt you, starting with your wallet and going from there. I didn't take this step myself, but it definitely made me pay attention to what I was doing.

First, using a DVM, check that the black wire at the rear of the dimmer indicates 0 Ohms to a good, solid ground. Next, check for voltage between the Blue/Yellow wire and ground. With the headlight switch on you should get 12 volts here, and 0 volts with the headlight switch off. Assuming this is okay, check for voltage between the Red/Yellow wire and ground (with the dimmer connected). With the headlight switch on, read this voltage while adjusting the dimmer through it's range. If the reading varies between 0 and 12 volts, then the dimmer is okay, if you get 12 volts regardless of thumbwheel position, the dimmer is dead. By now, you know what you need to do.

 

Money well spent.

Congratulations! You are a pioneer in the dash lighting area!

Every experienced technician has encountered some BOB parts. (BOB = Bad, right Out of the Box)

Thank you for sharing your method for fault determination and repair. Your success story will save other Maxima owners from replacing a repairable dimmer control.

 

I got busy, summer travels, work trips, etc., and totally forgot to update this thread.

I finally took out the bulbs from my ACC unit and examined them--burned out. They were ALL gone. So for that kind of thing to happen, somewhere along the way a spike must've gone through the wires and toasted them. So, I'm ordering replacements. I'm sure they'll be expensive because they look Nissan proprietary. Where did you get yours?

Unfortunately, somewhere along the way all my lights in the rear defroster switch went too. It still provides juice so the rear window defogs, but both the night lighting and the yellow indicator are out. I'm glad to hear you were able to replace them, so I imagine it's not too difficult to take the switch apart?

 

Ok for the ac unit I think there are like 4 bulbs if I remember correctly, I went to the Nissan dealership and ordered them, they don't keep them in stock so it takes a couple of days and they will cost you about 4 or 5 bucks for each one. As for the defrost they don't sell just the bulbs, they wanted about 25 or 30 bucks for the whole unit, so I went to radio shack and bought some little project type bulbs that were the same as the ones one the defrost, I and put them in there....works fine and it cost me 1.50 for two bulbs. Each bulb is in a little plastic holster or something like that and the wire from the bulb wraps around this little plastic unit. What I did with the defrost is take the old bulb out and carefully installed the new one in there. Now what I think you should do if you want to save time and $$ is go to Radio Shack and get those little bulbs there for the whole ac unit and for your defrost. It will take a little time and effort to take the old bulbs from that little plastic unit but it will save you some $$. If you need anymore detailed information let me know..

 

Hi David,
I appreciate your quick reply! When I replaced my Security Light LED (put in a blue one), I faced a similar situation. The bulb was in a soft rubber holster, and the wires wrapped through them in a rather awkward fashion. It took quite a while to do it, but I finally got the contacts to line up so that it would work.

If the rear defroster bulb you mentioned is like the ones for the AC unit, wow--sounds like a lot of work. I noticed the bulb has a plastic holster, which means it will be hard to thread the leads through it. $5 a piece is pricey, but considering the time involved it's not so bad.

Do you know if the defroster bulbs are exactly the same ones as for the AC lighting?

Thanks again for your help!

 

I'm pretty sure that they are the same bulbs, but I know that the housing for the bulbs for the ac unit is a hard plastic holster, as for the ones for the defrost, they are in a rubber housing like you mentioned on that security light. Maybe you should go ahead and get the ones for the ac unit at the dealership and just do the ones for the defrost unit yourself cause it is alot cheaper to get those bulbs from Radio Shack and do those yourself, then to have to get the whole defrost unit from the dealership cause thats the only way they sell that thing. The ones for the defrost are fairly easy to do...

 

I agree. I'd rather do the defroster switch myself than shell out a whopping $30. Do you remember the code numbers for the bulbs you got at RadioShack? I'm asking because they've got a huge selection (I've purchased about 4 different LEDs). If not, I'll just try to match up the bulb shapes.

 

Sorry bro, but I don't have the #'s, but what I did was just take one up there with me and matched it up, I think its a 12v bulb though, and when you look at it it has longer wires on it then the ones from the defrost button, but you can just cut those off after putting them in their housing...

 

That's alright, Dave. I was planning on doing the match up like you said. Usually the new bulbs have longer leads, to be versatile for other projects, so cutting them is a definite.

 

When I did the LED's in my door switches, I had picked up a set of standard bulbs for the heck of it. Turns out these were exactly what I needed. Nice thin wires.

So, while watching a TV show, I re-threaded the bulbs in the housings of the defroster switch. Worked like a charm--my switch is illuminated once again!

The only difficulties I had were taking the switch out and reassembling it. You really have to push hard to get the switch out of the socket. When you take it apart to get to the bulbs, there's this little black piece that falls out--took me a while to figure out how it went back into place.

But sure enough, when I reassembled it, everything worked like a charm. Thanks for your help, David.

The holsters on the other bulbs are different. My suspicion is that it will be harder. I may just order the bulbs rather than going through this.

 

I talked with Infinity of Scottsdale, and they have these bulbs for $2.89 a piece. Definitely worth buying rather than trying to fix the burned out ones. The defroster bulbs were relatively easy, because of the soft rubber holsters. But the other bulbs have the leads elaborately threaded into hard plastic.

By the way Infinity of Scottsdale is very Nissan friendly. Everytime I call them, they are eager to help me. The only flaw I saw is that they don't think beyond your request (I had ordered a '97 replacement armrest console for my '95, and they didn't bother to tell me that the lid was not included--had to order separately). They didn't even ask me if I had all the necessary fittings (fortunately I was able to use them from my '95).