Hey Bob,

Wow this is a pisser....It's gotta be the most obvious thing in the world.

You are sure you have the Cbs in correctly and the two "Batt" posts are the ones that are bridged. Also, the ignition switch power is running off the "Batt" post of the 30 amp breaker, not the "Aux" post of the breaker.

Can you tell me, does it die when you pull the headlight switch out just to the first detent (parking lights) or does it do it when you pull it out to the headlight position.

Also, when the thing dies with the headlight switch pulled out to the kill position, do the brake and running lights still work? Or is it just plain dead everywhere?

Let me study your drawing some more. I'm looking at the possibility of a short between the headlight and ignition switch power wires coming off the 30 amp breaker. Or a shorted 30 amp breaker itself.

And one last thing, and I know you have probably told me 1000 times, but just confirm for me you rewired those breakers and the distribution from them EXACTLY the same as in your drawing above and the colored one I posted.

Thanks Bob.

 

Could it have a dead short in the headlight circuit? A headlight relay that's shorted?

 

I'm with you guys/gals, it looks like a short in the lighting for one problem. He has said that at times it doesn't start without the lights. Maybe the lights have also caused another problem, in the engine wiring. Looking at the large wiring diagram on page two if you pop both circuit breakers and comfirm they are open that will disconnect all light wiring and light switches. You need to get the engine running without any problems, then attack the light system. What do you think, chuck

 

I know it is, when I find it I'm going to feel stupider than I feel right now for being a guy who works with electricity every day and can't figure out a problem with this simple system.

I have it wired just like the diagram. I am pretty sure I don't have it miswired. The truck worked fine for the entire summer, it just started to act up at the very end of summer/early fall. If I had wired it incorrectly I would have had this problem from the beginning.

I pulled the switch all the way out. It doesn't do it all of the time. It seems to do it only as the truck is moving, when it's just idling I can turn the lights on without it killing the truck. It will slow the engine down a little while idling.

I think everything dies. I'm not totally sure, it's been over two hours. I can barely remember things that happen ten minutes ago. I do know that right after it dies and I try to restart it the battery drains pretty quick and then I have nothing. Let it sit for fifteen minutes and the truck will start right up.

See my reply above.

This system is so basic there is no headlight relay in the circuit.

I'll have to crawl under and through the truck to see if there might be a wire rubbing on something. Maybe the mechanical movement of the truck makes something come in contact with the body or frame and causes a short and has only gotten worse the more I used it. It might not have been bad at the beginning of last summer but just got progressively worse as I used it.

 

Well, what I'm thinking is a short somewhere in the vacinity of the 30 amp breaker that is intermittent and very mild. When it is active it bleeds off some voltage from the power going over to the ignition switch (thus the bad running or not starting [caused by the current pull from the starter which weakens the power for ignition] that clears up when it's powered by another wire). When he turns on the headlights which runs out and grounds in at least four lights, it is enough to provide a full on short and steals all the power going to the ignition switch, and the 30 amp breaker trips as well. Later the breaker rests and it all goes away. The mild short may also be enough to fool his regulator into believing he has excess flow coming in from the battery and restricting charge.

If the parking or brake lights work that means that the power is coming in from the starter solenoid via the ammeter (which if it moves at all is ok) to the 15 amp breaker is still intact and the short has to be beyond the bridge wire - ie between the ignition and headlight wire, or in the CB itself.


If the lights flickering is rythmic and rpm related, there is definately a shorting relationship between the two. However, if the parking light position of the headlight switch causes the kill , then the 15 amp breaker is suspect.

If you don't find any shorts, I might be tempted to replace both of the CBs. They go bad slowly and get progressively worse with time. I'll sleep on it and see if I can't pull something else out of it.

 

Julie,

That's a great theory!! It gave me a head ache when I read it the first time but it sounds reasonable. I'm going to print it up and take it out to the truck tomorrow and see if it works.

Thanks, I really appreciate it.

 

LOL! It gave me a headache to WRITE it.

If you don't find any bare wires, I'm really suspecting that 30 amp breaker.

 

Two thoughts... first, the CB's hot terminals are connected by a piece of sheet metal strap, could be a bad connection. Second, are you running a ballast resistor? If so, hot wiring the coil would create a spark as you run direct battery voltage to it.

 

No ballast resistor, just plain stock.

I figure it's got to be something that deteriated over time because I had it working fine for the summer of '07 and most of '08. It kind of came on kind of sudden. It happened at the end of the season and I was busy at work so I just stored it for the winter, you know when we get that white stuff we call snow and it gets cold enough to freeze water and your outer extremidies! Man, I hate winter!!!

 

One more possibility: A headlight switch that is shorting out. Try temp swapping out the switch for a simple toggle switch as see if turning it on produces the same results. Also an armature or field coil in the generator that is shorting out at high loads. That might explain the fact that sitting (and cooling) allows you to restart the truck. Besides worn brushes this was the second most common generator failure we saw at the service station.

 

Man, I'm printing all of this stuff up and taking it out to the garage tonight. It should keep me busy for quite some time.

Thanks

 

Is the generator making any noise (low pitched growl that changes pitch with rpm)? bad bearings or bushings in the generator may be allowing it to short out at different times. Take the fan belt off and spin the generator by hand checking for growl and/or any side to side play in the shaft.

 

Yep,

Mr. Spock once said: If you can't find where something is, then elliminate all the places it isn't then eventually you will find it - Logical.

So, if you don't see anything obvious, you can start bypassing or replacing the likely components that could be shorted - headlight switch, CB, Ignition switch. I'm not going to say I doubt it could be this or that, with electricity, ya never know. Could be a charging system problem, but I 'm not sure how that ties in with the truck dying with the headlight/kill switch. The regulator should shut down flow with backflow caused by a generator short, and power should flow in to the ignition and lights from the battery throught the 15 amp breaker. (So, that's probably it - LOL).

If you don't find anything obvious, I'd change out (test bypass) the headlight switch, swap out the CB, and try it again. If the headlight switch was going bad (like it was getting hot and deformed (causing one of the tabs to relocate) it may have burned the breaker in the process and they are failing in unison now. See the "over time" factor is in play too.

I doubt it being affected by High Tide in Wisconsin, and it's not full moon unto Saturday. Bob, do you have a licensed Witch Doctor in town?

OK, not funny - you're frustrated - I'll shut up

 

What me frustrate?

AX, I don't hear any noise coming from the generator. That's one of the first things I checked. I didn't turn it without the belt this time but before I installed it last year, or the year before, which ever, I spun it by hand to make sure it didn't growl or squeak.

 

Those push/pull light switches take a beating over the years and over heat. Sometime you can see the overheating just by looking at the switch shell. Also don't forget the high/low beam switch on the floor. These are stepped on to hard, kicked, liquid spills, etc. and can fail internally. I still think you need to correct the power source (engine wiring)then worry about the lighting problem, unless one repairs the other.chuck