I want to thank the forum and especially pmohr for the help on the gremlins under the hood thread. I'm also having some problems on the inside as well and hope I might be able to get some ideas on where to start.

First, I installed an aftermarket radio and couldn't get it powered on. Nothing was coming from the ACC wire from the harness, so I simply found another wire that was hot when the key was in the ACC position and split and spliced into the hazard wire. However, that is just a bandaid for the problem and not really a fix.

Additionally, my rear windows don't roll down and the electric locks on the rear do not work, neither visor mirror lights work, left power window mirror doesn't operate (but the right side does), digital clock doesn't work and the cruise control doesn't work (the green light comes on the dash when I turn it on, but it the steering wheel controls don't seem to activate or control it), additionally the fan adjustment light on the climate control system isn't lit up (though it does seem to come on from time to time), low fuel light never seems to come on (and I've run it as close to empty as I'm confortable doing) and when attempting to turn on the AC just to see if it works, it doesn't seem the compressor is kicking on. Finally, even though I've basically hacked the radio into working, the power antenna doesn't work. I'm assuming also that if you leave the lights on and turn the car off that there is some kind of "hey dummy turn off your lights" chime or buzz or whatever, but I don't have that either. On the panel dimmer switch, that works fine, but the interior lights don't all come on if you bring it all the way over.

I replaced the digital clock, no fix. I figured with as many electrical issues that were going on that it MUST be a problem with the BCM, so I replaced that as well and no change.

It's more of a thing of what *does* work on the interior than what doesn't. Gauges all seem to work (except the low fuel), hazard and defog works. Trunk release works, fan speed switch works as well and the switch between different vents. Power windows and locks work for the front doors and all the interior lights work (except the vaniety mirror lights).

So with removing the need for a replacement BCM from the equation and all fuses and relays seem to be good, what else am I looking at? I'm thinking very likely wiring, but my God, it seems like that is a bit extreme and with as many componets that aren't working, it could all be traced back to one or two central things that would be more easily fixed that a completely new wiring harness (which would cost more than the car is worth I'm guessing).

 

My first thought would be BCM and fuses, but you've obviously already ruled that out.

Definitely sounds like some major wiring catastrophe somewhere in the body wiring harness...I'd start with tracing the harnesses coming from both the fuse box and the BCM, see if the previous owner screwed around with anything.

Any sort of aftermarket keyless entry/alarm/remote start installed?

 

Hello again! lol

Nothing like that (as far as I can tell), but the previous owner had an aftermarket CD player put in and when I went to go hook up the new one, I noticed that the ground coming out of the factory harness didn't exist, so it was grounded with a wired bolted down to the chassis (actually one of the bolts securing the BCM). That's the only thing I can find so far. I found a spliced connector under the hood that was just laying there, but can't find anything under there that it would have gone to. The horn connector was either cut or something as well, but I reconnected it and it works fine.

I see where a harness is coming through the firewall between the engine and cabin and going into the fuse block, but honestly I'm not sure where to even begin to start testing or what I should test for. The wiring diagram in the back of the Haynes manual got me started with the radio and a way to be able to hack a ACC hot wire from another working device, but other than that, I'm definitely a newb here. I've never done anything much more advanced than playing around with stereos and some minor stuff like swapping out switches, etc.

 

I noticed that the ground coming out of the factory harness didn't exist, so it was grounded with a wired bolted down to the chassis (actually one of the bolts securing the BCM).


well, I'm no electrical engineer, but when using a ground around a somewhat sensitive device like a BCM you or the previous owner could have jumped a spark or changed a flow variable in the car. just finding a ground anywhere is not always a great idea, especially close to other electronics. try grounding the radio somewhere else, might not fix the probs, but may help in some of them coming back later.

 

When I swapped out the BCM's, I didn't plug the radio back up or ground it, so I do know at least that isn't going to fix the issue, but that is a good idea on locating the ground elsewhere in the future. Thanks for the suggestion.

 

I would double check your audio power connections. If you splice into a power wire/connection if the splice is not done properly you can interrupt the flow of power (12vdc) to other circuits. For example in one of the posts the Maxima owner said that he got power for his radio from the lighter circuit, if that connection was not made properly it can cause wipers, mirror defrosters, clock and other circuits to go out. Your problem sounds similar. If you don't find anything else you may consider removing your aftermarket connections and returning everything to stock just to see if it gets things working. Most of the electrical problems that people post about are ones that that they caused themselves. The electrical systems of Maxima's are pretty reliable.

 

Try finding the cause of one circuit failure and you may fix the rest, keep it simple. Example, the vanity mirror light circuit is very basic. Check Fuse #40 (7.5) amp this is the vanity mirror fuse. You should measure 12VDC from ground to both sides of this fuse. There is a yellow with green strip wire that runs to the mirrors. This wire must have 12VDC or the mirrors will not light. My guess is it does not have 12VDC. Also check for any splices that may have been made to the accessory relay under the hood that could also cause these type of problems.

 

When I first got the Maxima, it didn't have the radio plugged into it anymore (previous owner removed it) and these issues were still there... it was just simply the stock harness left hanging (minus the ground terminal of course).

I haven't checked the wiring under the hood extensively yet, simply swapped out relays to see if that made any difference. I'll give these all a check tomorrow to see if that might be an issue. Supposed to warm up and will be easier to heat the garage.

Thank you for the suggestions.

 

Good luck, if you can give me some voltage measurements (just 12 VDC present or not) at some of the circuits I may be able to help. Let me know wire color and exactly where you are checking. I have the wiring diagrams and understand how to read them.

 

As far as rear windows not rolling down have you checked the safety lock that prevents this? This is so kids don't roll the windows down?

 

Check Fuse # 40 (7.5A) and fuse #21 (10A) very closely, even consider changing them. Pull them out and take a good look.

 

Yep, checked the safety locks and the fuses as well. Swapped too and nada.

 

The BCM does have some control over the power locks and the power windows but it has nothing to do with the Vanity Mirror lights or the clock. Clock requires the ignition switch to be on but the vanity mirrors don't even use the ignition circuit. Check if you have 12VDC at Fuse #40 and #21 with ignition switch on. If no 12VDC at these fuses many circuits will not function.

 

Please feel free to do this to me. --->

Wow, I'm feeling stupid right now. I've been scratching my head over this for a couple of weeks. Nopike, you hit the nail right on the head. I pulled fuses 21 and 40 and was testing the voltage and they tested good. I was getting ready to put the fuses back in when I noticed something, now that I looked at the fuse block layout again, I *seriously* don't believe that I checked fuse 40 and wouldn't you know it, it was broken.

Rear windows work, vanity mirrors, security, window beep, clock, power antenna, etc all work now. Even the door switches light up, which I wasn't aware that they were supposed to, lol.

So basically, the only things that aren't functioning at this point in the interior seems to be the left mirror control, ashtray light and a light in the manual climate control. I'm guessing that is probably a faulty switch and a couple of burnt out bulbs. I haven't had a chance to check to see if that is the problem with the cruise control and AC yet, but I will come back and update.

 

Not the first time some has told me all their fuses are fine when they are not. Glad you found it.

 

I had that same problem, I replaced fuse 40 and it worked great for about 2 weeks then I went over a railroad track and it blew instantly, I don't know if the railroad track was the reason but, I replaced it again and it just blows everytime I turn the car on...

 

You are shorting out one of the many circuits protected by this fuse. Any aftermarket electronics? Radio? That's where I would check first. One of those circuits has a short. Do you or someone you know have an ohmmeter/multimeter and know how to use it? If yes maybe I can help.