Briansmi1116

So, my truck won't start unless I turn on my dome light switch. I've traced it all the way to needing a ground tied to the orange wire behind the dimmer switch. When I do that, it turns on my light. When the ignition is off and there dome light is off, the battery saver relay clicks. I also measured 4 amps from the battery. When I turn on the dome light, ther clicking stops. If I remove there fuse for there battery saver and interior lights, the dome light doesn't turn on and the measured amps is .008. Any ideas?

Efarmer

One heck of an anti theft system IIRC it has something to do with a bad ground. Somewhat common as these trucks age and begin to show it.

River1

I have no idea what's wrong with your truck. If it were my truck the first thing I would check is will the truck start without turning the dome light on but by opening one and then the other door. And then both opening both doors. Since the dome light is part of the CTM or GEM module functions it would at least help in narrowing down where the problem is. If it does start with a door (s) open than I would think the problem is with the CTM or GEM, whichever one you have.

Briansmi1116

I've tried the doors, it seems to need the switch on in order to work right. I would agree with you on the CTS/GEM if the orange wire goes to it to tell it to turn on the fine light, but it still sounds like the ground is not getting too ther correct point as well. I just don't know where to start to locate the grounding issue. Could it also be that a12V wire is shorted to ground? If the dome light switch is off and the ignition is off, the battery saver relay is clicking. The battery is brand new so it's not a bad battery. There is a 4 amp draw as well.

Briansmi1116

It basically needs the switch on in order to start the fuel pump and the instrument cluster to start the engine.

River1

If you have a VOM look at some of the you tube videos on how to check for parasitic draw on your battery. Doing this is often referenced to the battery going dead, don't get caught up in that. With everything off and anything that will work with the truck not running disconnected or prevented from working like the light under your hood, after your computers power is drained off you should have no more than 2 to 5 milliamps, depending on the scale you're on. Your 4 amps may or may not mean anything. With your additional issues it sounds more to me like you have a power to ground short than a ground issue. From here I'm just guessing though.

Here you go:

ProjectSHO89

You have a bad ground. Pull both kick panels and inspect the grounding studs and connections. Look for body rot.

Reports of similar failures have skyrocketed recently in which certain electrical circuits exhibit unusual and seemingly illogical dependencies. In pretty every case that I've been involved in for which feedback or followup reports have been provided, it's due to a ground circuit that was compromised.

white89gt

I concur, bad ground. Somehow that circuit is finding ground when you turn the dome light on.

Jbrew

I've experienced the dome light itself causing strange issues in the past. Out of the blue it can short right at the ground on the fixture. If I recall this correctly, there's a small screw on the back that rusts up. When it does it shorts resulting in goofy electrical problems.

ProjectSHO89

Short circuits (to ground" usually cause smoke, fire or blown fuses, Short circuits to other things cause some other things to go wrong.

This isn't a "short "circuit instance, it's essentially a "long" or "detour" circuit.