20R 4cyl
4 speed
4x4 truck

K this is what my dumb <img src="/forums/images/graemlins/butwiggle.gif" alt="" /> did.
I was going to change out the starter because it wasn't any good. I didn't have a ride..so I removed the starter pushed it down the driveway and jumped in popped the clutch.
Cool, I am on my way to go get my new starter.
Well, on my way home. The positive side of the battery cable grounded out against the engine. I know, I know, but seriously I forgot about the hot battery cable just hanging down.
Now I have no power to anything. no headlights no parking lights no brake lights no radio no nothing.
yesterday and today I have replaced the alt. battery, voltage reg. ignition switch/wire harness and two relays that sit above the steering column. (one was burnt out) I have torn into the wire loom from the battery cable all the way to the fuse box. On the ignition switch...I get power to it on the Aux position and nothing when I try and turn on the engine.

As for the head lights...on the relay I get 12.7 volts until I flip the switch the the wire next to it goes down to 4 volts or lower. I traced it all the way to the fuse box and stopped their.
If anyone can help I thank you? I'll take bypass and rewire any section just that I drive it on the street so I do need everything to work ie..lights, turn singles and such.
Thanks,
Mike
IF anyone in the SATX area pm me if you would like to help out.....any time....A friend off the net hit that bad boy until 315am this morning..I am off the weekend...post up if you have Ideas.
I dont have dash lights as well.

You probably fried the ground wire for the engine block....verify that it is good. It might be located on the backside of the valve cover area.

K Zuk I will check that...I saw it their but I didn't take a good look at it....would that explain why I dont get no power anywhere?
Mike

Could it be that your battery fused open? That can happen with a dead short of that magnitude. It may show 12v with no load and then go down close to ZERO volts with a small load applied. Best to remove the battery and have it checked out at AutoBone or equiv.

Zuk I have tested the battery it checks out okay(had it tested at Azone with the alt. and replaced the dead starter that got me here). Replaced the starter. checked the alt. that is good. replaced voltage reg. replaced two relays above the steering column. One was blown. I have power when the key is turned to aux. and when I turn it to turn on the truck...I get nothing. The power just dies. I have replaced the ignition switch too. I am thinking their has to be a short some place. Same with the headlights. I get power on the off position 12.7 volts going to the relay. I turn the lights on and it drops down to 4volts on the wire that is just next to it. So I am thinking the short has to be on that side of the relay...if I get good voltage on one side and it drops down on the otherside. I checked the FSM for a 85. but doesn't have anything for a older truck. My hanyne suxs.. I'm going look more into it tomorrow. I have my truck torn apart beyond normal. I stripped the harness from the battery all they way to the fuse box and can't find anything burnt. I get power to the ignition system and coil./alt. But when I turn the key forward pass the Aux position everything dies...meaning I loose power.
Mike
Keep your ideas coming I need all the help I can. I will check that ground cable at the back of the valve cover tomorrow when day breaks.

One option is to start at the battery and measure the voltage at the post, then the cable clamp on each end and work your way along until you find where the voltage drops off suddenly. That will help isolate the source of the problem.

I agree with 4crawler...start at the battery....your DVM multimeter is your best friend for this issue. What you want to do is find where the volts changes from 12 to 4 volts....so with the headlights on you will measure 12 volts at the battery I guess....leave the lights on and move to the fusebox and measure the output side of the fusebox that goes into the cab. What do you see...volts?

One more thing.....check the ground wire on the battery itself...is it fried?

Ground cable on the battery is fine. But I will have to trace some wires.
THe white off the battery checks out fine. IT goes all the way to the alt. I have a red/blue and a Black/red wire that comes off the battery that I need to keep checking. Plus that ground wire at the back of the engine bay.
I'll keep you all posted on my findings.
Mike

Sorry to hear about your electrical problems, believe me, I know things like that suck, 20 years as a Navy Electronics Tech. has shown me alot of stuff. One thing you can do is start unhooking things. I mean unhook everything from your power source one by one, eventually you're gonna find the line that has the short in it. Suppose you could just start by yanking all of your fuses out, if that isolates it, put them back in one at a time. Or if you already have everything unhooked, than put it back together, one by one. There's usually no quick and dirty way for a problem like this. Of all the problems, primary power takes the cake for weird $h!t happening.

Good point about taking off all the fuses. I feel that it has two problems..the headlights and the ignition.
I'm going to check on it this evening when it's not so hot outside. My neighbor told me about this really good mechanic a few houses down...Think i'm going to talk to him and see what he thinks it can be after I check a few things.
Mike
About the Navy. I retired as a BM3(4yrs inn). Being color blind doesn't help me here at all... I'm going to get some tape and label the three main wires coming off the battery as 1-2-3 so that I can better identify them and not strugle with the colors so much.