Automatic Seatbelt/Accessory Power Problem (1991 Nissan 240sx SE)

[xs04298]

Thanks for at least taking an interest to start.

Problem(s):

Automatic seatbelts only work when key is in the "on" position. AKA they wont open when I open the door to get in, and they dont open when i shut the car off and open the door.Radio Constant lead has no powerDoor Adjar idiot light, and brake system light stay on (checked ebrake sensor, and swapped to known working door sensors)

only life i see when I put the key on accessory is that the backlight on the clock lights up (no clock, probably busted). The windshield wipers also work, so the ignition switch obviously works.

Blower motor does not come on, windows dont go down, nothing works, radio accessory 12v line DOES get power, but not constant)

Have checked: Accessory relay (switched with working)All 15A fuses (while searching I read that someone had a similiar problem, and they replaced a 15A fuse to fix it, granted the only 15A fuses in the fuse box are labeled blower)

Now I am at a loss, there is really nothing else in my book of knowledge to check.

If you have any suggestions at all I'm willing to try it, Thanks again for your interest.

Modified by xs04298 at 4:29 PM 7/24/2008
Modified by xs04298 at 4:44 PM 7/24/2008

[xs04298]

Hopeless? Its okay you can tell me.

[xs04298]

someone once told me third bump is the charm

[Hijacker]

You only checked the 15A fuses? I would check them all. Also, make sure that both your accessory relays are turning on when th ekey is put on ACC.

As for the seatbelt issue, I've seen door harnesses get chewed up from years of opening and shutting (and idiots who suck at wiring audioo) and the ground gets broken for the door latch switch. It should have a red wire and a black wire running to it on the driver side. And a blue and a black wire on the passenger side. What you can do is manually ground out the switch to see if the seatbelts starts to move.

However, I have a feeling the 10A fuse in the right column 3 down of your interior fuse panel is blown. Or not making contact at all. It's a constantly powered fuse that supplies the constant power to the radio, chime, and seatbelt module.

[xs04298]

Someone responds!

I've checked almost every fuse in the box, if not every fuse, as well as the door switches (they looked fine but i did not try grounding myself, I will indeed try that!)

You said both accessory relays, I know of the one blue one under the intake, and that one had 12v, is there another one hanging out somewhere?

Thanks a million for at least adding your brainpower

[Hijacker]

The other accessory relay is behind the fuse box inside the car. Pain in the rear to get to.

The door switches are hard to inspect as the switch itself is internal and requires destroying a good amount of plastic on the latch to get to. A good method to test the wiring would be to unplug the latch switch and complete the circuit with either a test light or a spare piece of wire. I prefer test light because you can ground it to the door and touch the light to the positive wire and get the same result as jumpering the pins (good way to see if the ground or constant are broken IMO)

[xs04298]

Well you sir are onto something. I checked the 10a fuse 3rd down right hand side, it had a 15a fuse in it, , but when i replaced it with a 10a fuse, it blows instantly, and in the name of good taste tried it twice and it blew the 2nd one instantly as well.

What causes those to blow anyway, a short? (not much of an electrician can you tell)

[Hijacker]

There's a short somewhere on that line. It could also be backfeeding as well.

Everything that is associated with that fuse is:Interior Lamp (Interior, spot, foot, luggage room, trunk room), Radio, Audio, Clock, Warning chime, Time Control Unit, A/T control unit, Head-up display control unit, automatic seat belt control unit, HICAS control unit, Auto antenna timer

Granted, your car doesn't have every one of those things, but it will give you a good idea of what to look at.

What confuses me is that your windows don't work and your blower doesn't work. The windows are tied to the ignition relay, and the blower motor is tied to the accessory relay in the engine bay.

[xs04298]

someone had cut the ingnition wiring harness at one time, well not cut by they put maybe half a dozen 3 way connectors on the ignition power leads. I went in and cut all those out and put butt connectors in their place, all the ones I found anyway, I really do not have a clue what they were intending to do with all of this :

(keep in mind the blower and windows do work when the car is "on")



and on the 10a fuse thing, could that have more things on that one fuse But none of those things work, not even sure where to begin looking for shorts lol. My gut tells me to look at the lights first

[Hijacker]

The windows and the blower are only supposed to work in the 'on' position. They're driven from the ignition relay, not the Acc relay (the blower motor itself gets power from the ACC relay, but the HVAC control is ignition relay)

Can you list the colors of the wires from left to right in your picture?

[xs04298]

Will do that first thing in the morning, going to take all the covers off for the column to make sure there is no more hacking of wires.

I can tell you the far right circle is a red/black wire that led to an LED light that someone had put into the shifter console.....might be a clue as to what the wiring was for

[Hijacker]

That was done for a security system. The red/black that should be inside the harness that leads trhough that is tied to the radio/auto belts fuse I was talking about earlier. I'm wondering if whoever installed the security system was being cheeky and using the same colored wire from what they tapped off of.

I just wish some audio/visual installers would take the time to not be so sloppy and obtrusive into the factory wiring harness. They always create more problems that way.

[xs04298]

Sorry didn't get the wire colors, had bigger fish to fry today with engine troubles...from there i will just try and find the short in that system i suppose...

thanks again for all your help

[xs04298]

left to right: Black/Yellow(altered) Green/Yellow(unaltered) White/Red(altered) Black/White (altered) Blue (unaltered)red/blue altered wire, runs to headlight up/down switch (???) red/white footlight altered

all the ones that are listed as altered had 3 way connectors tapped into them, i removed all of those and sautered or butt connected them back together.

I unpluged almost everything on that circuit, and its still blowing that fuse instantly, I will continue to dismantle the interior though it certainly seems like a positive lead is shorting on something...somewhere