Electrical problem... fuse box in engine bay has power, one in car does not

[natedog437]

just bought a 95' 240sx with 125k miles and it cranks up fine, idles fine, head lights work.... but NOTHING else works on the inside of the car. The windows, guages, odometer, blinkers, wipers, sunroof, A/C fan, heater, PDL, etc.... do not work at all. They will randomly come on out of the blue for a few seconds... which is suspect, because that means that the fuse is not bad.

I replaced the ground wire to the battery, terminals on the battery, the battery itself, and checked all the fuses. The fuse box under the hood by the battery has power, but upon checking the fuse box inside the car by the clutch pedal, there is no power getting to any of those fuses. At one point, everything came on and it all worked fine, but a few minutes later, it went back off and stayed off.

Anyone have any idea what might be the problem here? Thanks

[LEMHEAD16]

check for fusible links that are melted somewhere along the line

[natedog437]

could it be my alternator? I found out that the car had been sitting for a year or so before I bought it. Would the alternator possibly go bad becuase of sitting and not being used?

[natedog437]

I checked the fusable links. They look good

[natedog437]

I'm thinking it's the alternator and here is why... A couple of days ago when I was enitially test driving the car and it was doing it and then it started to sputter and then completely die! I rolled it and popped the clutch, then drove it to meet my friend for him to look at it. He turned his 240 off and we dropped his battery in my car and everything worked fine. We parked it and then I put the other battery back in and nothing! Like I said, I put a new battery in it, and it didn't fix the problem. I got home from getting the new battery with it hooked up on the car, turned it off and did a voltage check. I'm getting no more than 11.88 outta the thing and while the car is runing it seems to slowly drop in voltage. I just my car off with another car that was reading 13.9 while running and left mine connected and tested mine. It was still around 11.40 and dropping really slowly. Think I am correct on this?

[Dattebayo]

Its not the alternator that would be a problem.

First off the voltage regulator inside the alternator is shot. Solution = replace alternator or take apart and rebuild with new regulator. Check the connection at the regulator as well because i think all inside power is run through it. I will check the wiring in the FSM for you if you like.

[Dattebayo]

I confirmed that inside power IS definately routed through the voltage regulator. I would try that first, but there could be a million issues because the power goes through many connections.

[natedog437]

So if I just replace the alternator I should be fine right? I have a new one on the way and that will completely replace the voltage regulator right? Is there a chance that it will happen agian? The voltage regulator is inside the alternator right? Should I replace any of the wires coming from the alternator when I replace it?

[Dattebayo]

Just make sure the connetor is not damaged in any way. Also make sure you get a factory alternator partstore alty's are crap. All of them. Only buy Nissan alternators.

[natedog437]

Well I guess I'm screwed then because the quickest one I could get here quickest was a duralast. I have one on my truck and it's been on there a year with no problems. It's got a lifetime warrenty and I got the SE 90 amp alternator even though mine isn't an SE. Oh well, it's too late now, but they will let me get a full refund if it's no good, and then I will just order a factory one. Do you know any good places to get an OEM one?

[natedog437]

Well I just replaced my alternator and I saw the lights on the dash come on while the key was turning over and then when the car was cranked...Nothing!! I'm getting reversed polarity reading coming from the alternator and I'm thinking that it blew. The batter was outta the car the whole time and yes everything was hooked up correctly. What the hell is going on with my wiring?

[Dattebayo]

Are you sure the battery wasnt in backwards?

It is possible to put it in backwards...

This is the proper way:

[Dattebayo]

And this is the wrong way:

[natedog437]

Honestly how could that matter the position that it is in as long as the positive terminal is on the positive is on the negative? My battery and my friends 240 battery looks like the correct way to position it picture, but our posts are on the backside(i'm positive it was in correctly). I checked the fuses under the hood agian and the ones that say A/C, Radio, and ALT'S are not getting power to them. What should I do? Trace the wiring from them or something?