DragStuff

OK, Trying to get my tow truck set up for the summer. Got a new trailer. So, it I leave the batter hooked up, in about 3/4 days it goes dead. I tried disconnecting the negative batter terminal, then put a test light in between, pulled all the fuses and the light stays on. So, where do I go from here? I am looking to rebuild the engine/trans. What else can be causing a short like that?

what kind/year of truck... later vehicles will have fuses both to the side of the dash AND under the hood. Your going about it, the way i would tell you to. need more info.

It is a 1994 C1500 Silverado. It's the 5.7/4l60e with 3.42 rear end. When my dad had the truck, he had a brake controller installed, and I have pulled the trailer, the brake controller works. It has had a short in it when he had it. He never services or fixes anything, it goes about three days and its totally drained. It is the TBI.

Like I said I pulled every fuse under the dash. Hooked the test light in between the Negative Terminal and it stays on. Here is another issue, the power window switch on the drivers side for the passenger side doesn't work, the driver's side does work, and the passenger side switch works on the door. I was thinking maybe an exposed wire there? But with all the fuses pulled, it should be a dead circuit right?

try some unfused items like the alternator and starter. diconnect the battery, then the alternator, then put In your test light.

did ya ever find it?

No I haven't, I pulled all the fuses, and left it there, its been too cold to go outside and work on it. gonna disconnect the starter / alternator next. Track it from there.

Ok, Finally got some nice weather here in Lovely Northern Ohio.

I put a test light in between the negative terminal, took negative cable off, and put the pin in the cable, it was on. I took every fuse out, Light is still on. I took the junction off of the firewall, found the one powering it everything, then took all the others off. So took the starter off, which is another issue, the wires look horrible and there is some sort of sensor in the block with the wire hanging. So, I took the 3rd junction off and the test light went out. I traced it to the underhood light that is right above it. So, with all fuses out, and the test light clamped from the negative terminal to the negative batter cable, it is now off. So I just took that light out, It worked, but could it have been shorting and the cause? I am going to fix the sensor under that goes to the block and fix all the connectors on the starter. start putting all the fuses back in and make sure the test light does not come back on.

Keep everyone updated on this sucker. I need to go get the trailer and make sure all the lights work, then that will be it on those two for a bit, back to the brake system on Camaro.

Hope this is it.

Sorry, I should have posted, this, after I put it all back together, the test light came on, I had the door open, pulled the dome / gauge fuses test light went out. Now to fix other stuff.

Ok, Really scratching my head. I traced everything down and found the mercury light, so figured it was all done. Then I buy this fancy LED sound test light, hook it up to show my wife I fixed it and it comes on and beeps. I pulled all the fuses. Still beeps. Pulled all the wires from junction and disconnect the alternator, still beeps. I pulled wires from my positive side, since I have a few different ones. The wire for the brake controller, when that was removed, stopped the beeping. My dad had this hooked up 12/15 years ago. The wires appear to be hooked up correct. I wouldn't think so, but the controller is a Reese POD, whats weird is that it says the black goes to positive with 30A breaker, and white goes to negative, blue goes to the rear of the car. Can any of those wires in the back cause this? I have a new 7 round connector to hook up. Any help is appreciated.

I have had one of those go bad after a few years, and it would drain my battery. I never used it, but left it on in case I needed it (was on the truck when I got it). Didn't affect the brake lights, so I didn't have any thing to point me in that direction. I found out it was bad when I chased stuff around like you and finally hooked up to a friends camper that had trailer brakes and the brakes on the trailer would stay engaged until I pulled the fuse...