Jmartinez

What's up guys. I have been fighting some weird electrical issues in my maxima and stumbled upon yet another. I'm trying to clear my CEL codes with the obd2 scanner and to my luck the scanner doesnt power up when you connect it to the port. I tested the scanner on a few other cars to be sure it wasn't bad. It worked fine.

To go back a little I'll tell you what I was doing before all this happened(I was always able to connect my scanner with no isssues before)

First my brake lights fuse kept blowing, turned out to be old bulbs that were shorting themselves out. After I fixed that I noticed when I turned the radio on I would just get a buzzing noise coming from the front right speaker that gets louder when you hit the gas (bad ground?)
I yanked the radio and harness out so I can solder the wires together.
Everything is still out of the car at the moment

Since all this has happened I can no longer connect my scanner to the car to clear the codes. I checked the ecu to see if the screw was ever moved and it the tape was never taken off.

I've searched the threads and have found people who had the issue, fixed it but never said what it was. Some people said it was a fuse. I've gone up and down the fuse blocks and can't find any blown fuses.
Seen people run a new wire but it didn't say where this wire went to but it's just weird how it was working fine all this time.
Also noticed my clock not working.

Any input would be appreciated. Thanks

DennisMik

iTrader: (2)

One of the pins in the OBD connector has 12 volts on it to tell the scanner that the car is on. If this pin does not have power, the scanner may not do anything. Depends on the scanner. Maybe a fuse is blown that powers the OBD port, but I don't know what fuse it is.

On the clock, how does it not work? Does it light up and show 12:00 or does it not light up? Fuse #40 to keep time and fuse # 21 to light up. But since you took the radio out, did you double check that the connector on the clock is on tight?

Amerikaner83

iTrader: (17)

the clock not working may not be relevant. The clock on the 4th gens suffers from poor solder on the circuitry, a simple retouch of a soldering iron and addition of solder should help. That was the first "mod" I did to my 99 when I bought it in january.

AznRyan

iTrader: (1)

I dunno about the OBDII issue, but I know that sometimes a fuse can be bad, even if it looks ok. I thought I was losing my mind once, trying to track down the problem. It was a sneaky blown fuse (not the same problem as the one you're having, though)

bobflood

Look for power (+12V) on pin #1 of the OBD port. Should be getting power from Fuse #40, which is hot at all time.

njmaxseltd

iTrader: (19)

Plug the radio back in and give it a try.

fulloboost

Had same problem but it was one of the electrical fuses..

Jmartinez

Thanks I will try this out.

njmaxseltd I thought about it but I need to redo the wire harness and solder it all together since it was all hacked up. Looks like someone stole the old radio and cut the factory harness.

As for the clock I only threw that on there because I saw alot of other people with the same issue and figured in some dumb way the two were related lol.

Thanks for the input fellas I will try this out tonight and see what I get.

DennisMik

iTrader: (2)

I couldn't recall where I had seen this in the FSM. Thanks for the slap on the back of the head.

However, fuse # 40 is not hot all the time. Fuse 40 is fed power by the ignition switch in the ON or ACC positions. Reference 1998 FSM EC-471, 1997 EC-381

Good point. This may help the op. Pull the fuse out and look at it from the side.

bobflood

Dennis: I really hate to disagree, given your level of expertise I have observed, but according to both the wiring diagrams in the online data base I use, and my copy of the 1997 FSM (EL pages 6-11; Fuse #40 is fed from the battery via 75amp fusible link "k"), Fuse #40 is always hot. If car is at home tonite (stepdaughter is primary driver) I will try to go make a measurement to confirm. Thanks.

GGENIUS

iTrader: (1)

i think the guys point was that fuses can be blown without showing visual signs of broken linkage. get a test light for a few bucks, and you can actually check fuses efficiently.(this goes to anyone who wants to make their future diagnostic efforts easier)

AznRyan

iTrader: (1)

Yeah, even looking from the side I couldn't see any sign of a blown fuse. No dark spot, no gap in the metal, it looked fine.

DennisMik

iTrader: (2)

Well Bob, you are correct.

On my 97, pin 1 of the OBD port is hot all the time. I even pulled fuse 40 out to make sure that was the fuse. I picked the wrong page of the FSM to believe in.

The power supply routing page (block diagram) in the EL section is correct, but the MIL/DL schematic in the EC section is incorrect. Make a note in your manuals, guys, so you don't put your foot in your mouth like I did..

Jmartinez

Thanks for the help guys. Turns out fuse # 40 was blown, wish I could have taken a pic but it was too dark at the time. When you look at it from the side it looked fine, but when you bring it up closer you can see towards one side of the fuse had a split in it. Threw in a new fuse and bingo power to the plug once again. I appreciate the help guys, love the fact that there is no bashing and people actually work together to fix an issue. I'm used to 3-4 page arguements before a problem is resolved. Thanks again.

bobflood

Oh, we have those too - just start a thread about regular vs premium gas and watch the fur fly!!

AznRyan

iTrader: (1)

In my experience, the ones that get/deserve bashing are the ones that spread false information, or do a bunch of tacky/pointless mods while insisting they're ride is superior to everyone else's.

(I think I just described Clashez )

Mattyboy

iTrader: (1)

Ok guys, def as new as can be to this and the "15 post rule" I can't start a new thread as of yet. Nevertheless, I'd appreciate any insight on my situation. Here it goes, bought my 00 max with a cel light (stupid move I know) but the car ran fine with the exception of a squealing belt (now fixed) on my way to the parts store the car began to misfire randomly (starts and stops the misfire sporadically) and occasionally hits what seems to be a "dead spot" in acceleration. Went to get it scanned and the scanner can't connect to the car (ports dead) Nevertheless I pop off the lower dash cover where the obd port is and low and behold it seems as though all the wiring has been cut and spliced and butchered. Was wondering if anyone would know what wires I'd need to check to power the obd port. No mods done whatsoever. Shes bone stock just coiloves that were way too low now raised. Please help guys

DennisMik

iTrader: (2)

Maybe the car had an aftermarket alarm that was removed? Who knows? All I can do is give you the wire colors and what pin they connect to and you will have to find them and repair them. But if you read all the posts in here, check the fuse that goes to pin 16, the scanners use that to determine if the car is turned on. Pin 8 also has power when the ignition switch is on, but I don't think OBD uses it, it is for the Nissan CONSULT tool. But check it anyway.

pin 1 - brown
pin 4 - black (ground)
pin 5 - black (ground)
pin 7 - orange
pin 8 - green (switched 12 volts from fuse # 10)
pin 11 - green/yellow stripe
pin 12 - pink
pin 13 - brown/yellow stripe
pin 16 - yellow/red stripe (constant 12 volts from fuse # 12)

Mattyboy

iTrader: (1)

Dennis, thanks for the reply. I'm gonna mess around with her today. Yesterday I checked all the fuses and all are good. I'm thinking its either some shotty electrical work or maybe even a relay somewhere. Only problem is i wouldn't know which relays to check. My top dash clock doesn't work (light up or anything) nor do my reverse lights. I've read somewhere that some relays control the engine control as well as some other components such as reverse lights and clock as well as obd port. I'm gonna remove the driver seat and lower dash panel today and try resplicing all the wires to the correct color code. Some of them aren't even connected to anything. It's really a mess down there. If I can ongoing to try to get a clear enough pic and post it so you can get a feel of what I'm dealing with here. I feel like the car is just lacking a little tlc and some patience. Just hope my love for the maximas hasn't blinded me again, had a 98 5spd SE that was a total lemon before this car and vested alot of time, money and "tlc" into it, she just couldn't be saved. Was better off a parts car lol

DennisMik

iTrader: (2)

I'd like to add that my wiring list is for a 2000 year car. I got that from you signature. If you have a 4th gen (as this forum is for), my list has no similarities with a 4th gen.

Mattyboy

iTrader: (1)

Yes it's a 5th gen max. I did a little work on her today. It has coilovers and when I got the car it was EXCESSIVELY low. The wheel well liners were removed as to compensate for space. In doing so he exposed the wire harness in the drivers side front well. I've raised the car up some since. Upon inspection I found 3 torn wires. Fixed them and got my reverse lights, horn and P,R,N,D illumination back. But still no power to obd port. It seems as though its most likely a faulty electrical wiring issue. And you were right, it did look as though there was an aftermarket "alarm" installed and removed. Once again ill keep you up to speed as I continue to work on the issue.