Electrical mayhem

[Dave7.3]

Well, I have been fighting electrical problems for quite a while now. From a swelled battery to a poor ground, I thought I finally had it worked out. Nope.

Got off work this evening and jumped in the cab, everything came on when I flipped on the key just fine. Turned the key to start and it made a half revolution before stopping. I have lost all electrical power, barely enough to turn on the dome light in the cab now.

I have no idea what is going on, tried to run jumper cables from my boss's truck but STILL not enough juice to get her going. Thank god it is a manual, pull started it and limped home.

When driving home, I noticed the rear anti lock light stays on constantly. Any time I touch the brake, the power dips terribly on my gauges (aftermarket voltmeter included).

I spent a good hour tracing all of my wiring and found nothing really out of place. No melting, nothing. Strangely though, when I jumped in the cab and went to push in the clutch, my fat foot caught the brake and everything came back full power! Then as soon as I turned the key to start, same as before. A half revolution and then everything went dead again.

PLEASE give me a hand here, I need her running by tomorrow morning!

 

[GenLightening]

Seems I remember there being a connection near the E-brake assembly that can cause issues.

 

[Dave7.3]

Just checked it out, the little connector is there...but I found something else when I pulled the panel for the fuses.

There is a black wire coming out of my Kelsey Trailer brake controller and the red wire it hooks to is just hanging there. Looks like it pulled out of somewhere. Let me see if I can run out and get a picture...

 

[Dave7.3]

Got a good picture of the wire described, pulled it down a little for identification.

Found out that some of the stupid locks I thought I replaced were hidden up behind that panel. I foresee more soldering in my future.

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It has a little wear on it, but not enough to break the insulation. Must have been rubbing against one of the pedals before dislodging completely. According to the guide I found online, that black wire to the controller is wired straight to the battery. It has to be it! But...where does it go?

 

[GenLightening]

Is it the feed wire to the controller or from the controller? Seems like it should go directly to the controller connection.Looks like the wire may have been spliced in a couple of times to make it longer. Maybe look for another one of those connectors that doesn't have another wire coming out of it?

 

[Dave7.3]

Thanks for the tip! It seems to go to the controller...but that means there is a power wire hanging somewhere.

Looking closely at the wire, it looks like it has been cut right off, no mark of a lock on it. I sure can't find a spot where it hooks in either...

 

[jim x 3]

Dave,

Did you get this problem fixed?

The black wire into the brake controller is likely +12V power to the controller as you surmised. The red extension of this wire goes to +12V perhaps via the ignition switch or other +12V source with ignition switch ON. Or it may go directly to a battery (perhaps via an auto reset circuit breaker) or other constant +12v location. It may have been fouled in the brake or clutch pedal mechanism and have parted. Check at the appropriate length for another end of a red wire. You may have an intermittent short to ground at that point. (But this would likely blow a fuse or fusible link, or melt the wire with resultant smoke and fireworks).

Is there a burnt smell anywhere? Does any of your suspect controller wiring get hot in the "Loss of Power" condition?

Good luck.

Regards,

 

[Dave7.3]

Thanks for replying Jim, I have yet to solve this...

I don't smell anything burnt and with the key on, the wires don't seem to be getting hot.

I did find a gray connector with one hole empty on the side of the steering column. But it is on the opposite side where the wire cannot reach. Is there a connector of some kind behind the column that I can't see?

 

[Dave7.3]

I got to thinking, where are the possibilities for that wire to be connected around the pedal area anyway?

I can't find a loose wire or connector missing in that location where I can see...but there could be something further up.

Also, I got to thinking...could the sensor for my brakes be grounding out? The power really dips low whenever I touch the brake pedal.

 

[jim x 3]

Dave,

Maybe the brake controller is a red herring. I expect the gray connector is probably OK. But if the brake pedal affects the symptoms then its somehow involved. Do the brake lights work properly? Do the hazards and turn signals work?

If this "loss of power" occurs when you turn key to START and you can't jump start from boss' good battery then maybe we are dumping large current through the starter (but not enuf to turn it over). Does the "loss of power" and low voltmeter reading occur with key in START but start relay defeated? The start relay is on the inner R side fender. You can defeat it by disconnecting the small wire to it (red w/ blue on 1988 model).

Good luck.

Regards,

 

[jim x 3]

Dave,

Are we constantly draining current from the batteries, even with the key in OFF? What is the condition of the batteries? Are you charging them?

If we have a current drain w/ key OFF, does it continue if you pull the stop lamp fuse? (#1 15A in 1988)?

Do you have a speed control system?

Regards,

 

[George D.]

Try disconecting the conroller and see what happens.

 

[Dave7.3]

Dave,

Maybe the brake controller is a red herring. I expect the gray connector is probably OK. But if the brake pedal affects the symptoms then its somehow involved. Do the brake lights work properly? Do the hazards and turn signals work?

If this "loss of power" occurs when you turn key to START and you can't jump start from boss' good battery then maybe we are dumping large current through the starter (but not enuf to turn it over). Does the "loss of power" and low voltmeter reading occur with key in START but start relay defeated? The start relay is on the inner R side fender. You can defeat it by disconnecting the small wire to it (red w/ blue on 1988 model).

Good luck.

Regards,

Sorry for the delay, I've been out under the hood for a few hours.

All of the lights work properly, but they are very dim due to the low power.

When the key would be turned to the key on position, the power dims and drops very low. Almost not enough to light the WTS light. When you turn the key, everything goes out.

When I did have the jumper truck hooked up, the power increased enough that the starter solenoid made a clicking sound. Not enough it seems to get through the solenoid.

The batteries seem to hold their charge for now...going to leave them unhooked overnight just in case it is shorted somewhere.

I do have a speed control system, which doesn't work either unfortunately (never has).

I am almost wondering if the older battery finally gave out...I had the other swell up like a watermelon and had it replaced. I'll have to test it out and see in the morning. Thank you everyone for the replies guys.

I am gonna sleep on this for tonight and see if things come together in the morning...

 

[jim x 3]

Dave,

Generally you want to replace batteries in pairs so that a weak battery won't negatively affect a strong new one.

You need to get your batteries up to ***** - charged while disconnected. Then you need to search for a constant current drain that would have discharged them. You may have a short (or intermittent short) somewhere or the good battery may have discharged thru the bad one.

Good luck.

regards,

 

[Devilish]

A few things come to mind regarding your problem
1. your regulator is taking a crap. It is located on the right fenderwell near the starter solenoid. I had regultors got bad on 2 trucks in the same week. First was charging at 18+ volts when driving. The other would barely charge and batteries were dead by morning.
2. You have a bad ground. Use a pair of jumper cables and connect batts to body and engine.
3. Bad battery. 1 bad batt will bring down both. You can use the jumpers to test the connections between the batts