Cascade Crew

BluFbdy · Posted: Mon Mar 12, 2012 2:46 am Post subject: Headlights crapped out....stumped

hey guys I'm having trouble with my wife's car. her headlights crapped out on me randomly I turned them on and a second later they cut out, car was sitting in the parking spot and I've been trying to t shoot it but e very wire shows a damn ground when the switch turns on I need some help, as usual TGO is useless soq maybe someones had this issue here, I posted there hoping the volume of members may chime in but...yeahhhhh.... anyway here's a link with the full story, I'd type it here but I'm on my phone like usual any ideas will be great this has me boggled

http://www.thirdgen.org/techboard/electronics/644446-headlight-issue-am-i.html

Dewey316 · Posted: Mon Mar 12, 2012 3:04 am Post subject:

Is your battery draining when the car sits? I am wondering if something shorted out, and is causing a draw.

You mentioned funky freying on the fuseable links, I would look into this some more, maybe one of them is somehow making contact with something and causing a drain.

Honestly, my only real advice is, to keep testing voltage, and work you way to the problem, it is pains taking, but you will find it if you keep following the low voltage, until you find the 12v. I fell your pain, I played this game for a while with my Audi project, I traced and checked every stinking connection for a week, until I found where the problem was. Between voltage tests, and continuty checks, you'll find it, you just have to keep working through it systematicly. Don't just try at random, you'll frustrate yourself that way.

If the radio gets 3v, then check the voltage at the next connection point for that wire, and so on so forth until you find where that circuit does have 12v at.

aaron_sK · Posted: Mon Mar 12, 2012 8:00 am Post subject:

My first thought was the switch (they melt frequently) but you said you've replaced that. If you have any question as to whether the switch is DOA you can bench test it with a continuity tester, test light or even an ohmmeter.

Replace all questionable fusible links with the appropriate gauge. They are cheap and easy to fix.

The car was very wet inside when you bought it IIRC, so don't rule out a poor connection in the fusebox or in a connector under the column. Water evaporates up into the harness and it will corrode the copper.

BluFbdy · Posted: Mon Mar 12, 2012 10:06 am Post subject:

ill have to do the switch with my meter i blanked on that, idk if the links are bad necessarily because mine are the same way, on the starter side theyre insulated but where it enters the harness its open wire, couldnt hurt to swap them though.

I probed my main power wires going into the c100 so i know from the battery to the c100 its good, i just dont know where the power goes once it enters the vehicle, ill get some electrical parts cleaner and go at the fue box its a bit corroded, nice white color to the terminals my problem is i dont know what each connector does exactly to determine the flow of power.

Another confusing part is the fact that jumping the wires did nothing, brown is parking lights correct? if i have power at the switch a fused jumper should either power the circuit, or blow out neither of which happened

anyone know the wire colors at the switch? knowing the purpose of the wires helps process the whole thing because i know when i power wire (a) it should turn on the headlights or the parking lights etc

red is constant
orange is constant
brown is parking lights
the rest is blank

aaron_sK · Posted: Mon Mar 12, 2012 2:56 pm Post subject:

Switch is in the upper center of this diagram.

http://austinthirdgen.org/mkportal/modules/contents/images/Fig56_1991_body_wiring.gif

There should be no bare wire on any fusible link. That is just craziness.

BluFbdy · Posted: Mon Mar 12, 2012 2:59 pm Post subject:

craptacular lol looks like I get to spend some time under the heap

BluFbdy · Posted: Mon Mar 12, 2012 3:16 pm Post subject:

So looking at this diagram the tail and instrument fuses are power off the headlight switch so i can isolate the issue between the switch and the firewall correct? my power wires have 12 volts UNTIL the switch is turned on because the switch is supposed to shift the contacts and if its grounding out at the switch that would explain the loss of power.

Only hold up to my theory is the old switch was the one that fried, this one was a replacement but its not switching the power which is where i find a red flag

sound about right?

aaron_sK · Posted: Mon Mar 12, 2012 7:17 pm Post subject:

I would pull the switch out and bench test it. Assuming it throws as intended I would then start probing the switch plug looking for something shorted out.