Electrical Problems Bigtime

[Meatchops]

m1009 guys, attention please...

from the title of this thread you might guess i'm having some issues...


it started out of nowhere. no headlights!

headlight fuse is good... all of the fuses that were there to start with are good(or have been replaced following some misguided troubleshooting effort).

i wound up jumping 12v from a socket in the bottom left area of the fuse block to the socket to the left of the headlight fuse for headlight operation when the ignition is on at least.

i've looked over all the documentation i can find and can't make heads or tails of where the 12v to the headlight fuse originates from...

any help is much appreciated. i've been tearing my hair out and trying to not tear too much of the wiring harness out... Thanks!

 

[Meatchops]

i should have said to start with, it looks like there's no 12v on the fuse block for the headlights, marker lights, brake lights(i think) or horn... the horn relay under the dash clicks when i push on the horn, only when the 12v is jumped on the fuse block though

 

[deuceman51]

Stupid question I know, but do you have the drive light switch in the right position? If it is not on, no headlights, no horn, no marker. You have to also put the switch in the lower BO mode and then toggle the momentary switch to turn on the Blackout drive headlight. I just had a soldier write up all those things as not working on a CUCV and tell me what a piece of crap our equipment was. I prompty went over to the truck and made everything he wrote up work and told him what a dumbass operator he is by not knowing how to operate the controls on his vehicle, lol.

 

[Meatchops]

haha... got it.

just to be sure i'm not a blithering so-and-so i checked it just now.

the way i have it hotwired the headlights and marker lights bypass the "all off" switch.

with it not hotwired i have no headlights, marker lights, brake lights, horn or blackout lights regardless of the position of the toggle switches.

with it hotwired i have headlights, marker lights and horn regardless of the "all off" switch position, brake lights when the "all off" switch is in the service lights position and no blackout lights at all...

maybe a bad blackout toggle switch?

 

[kennyw]

Pull the plug off of the black out switch and test for 12V coming in at that point.

 

[Crash_AF]

Have you checked the battery feed wire to the headlight switch? It is the orange wire tagged as 'Orange 40C' in the TM diagram to see if it has power? That appears to be where all of the lighting system gets its power from.

Later,
Joe

 

[mangus580]

When you say you 'got it' on the switch. You ARE aware the switch handle needs to be pulled out, in order to achieve the top most (on) position.

 

[Meatchops]

Kenny, there's no voltage out of any of the terminals on the service lights plug. Tested with the the headlight switch off and on, with the ignition off. I don't have my meter, but i fashioned one with two pieces of wire(one grounded) and my mouth...

Crash, the terminal on the fuse block that the Orange 40C wire in the diagram goes to has no power when i meter it to ground. That is the terminal i'm "hotwired" into from a different source on the fuse block. hope that makes sense... i checked that with my real meter a little while ago...

and yes mangus, lol the lights did work before...

thanks for the help so far guys!

 

[davidkroberts]

had a similar problem on a older civi chevy truck (same make) ended up being a bad ground. hard to diagnose from a computer.

 

[Meatchops]

i had ruled out a bad ground given that everything works when power is applied to the circuit via the fuse block.

I'm pretty sure it's a positive 12v supply problem... i just don't want to tear everything down more than i have to.

 

[kennyw]

Next place to check would be the fuseable links. Sounds like you have one burnt out.

 

[Meatchops]

Are the fuseable links the shorter sections of wire connected to the post next to the glow plug relay? < newb