Battery has been dying on the truck recently. I don't drive it often so I I just keep jumping it, but that's getting annoying.

Did some digging and used a multimeter to find parasitic draw. About a half amp. Narrowed it down to the iod fuse, but haven't been able to narrow further as there is a number of things behind it.

I ruled out the common ones, glove box and under hood light. Tried a few other options, looked for obscure lights, can't find anything.

I'm most suspicious of the power mirrors. But I don't know how to test. The actual reflective part of the mirror fell out recently and the heating element was unplugged. I tried plugging it back in (not exactly sure how it would help, just trying to put it back how it was) and I still got the draw.

Any ideas?

 

Doesn't say what year the truck is. Power mirrors is unlikely unless the switch is stuck on in one position. The heaters don't get power with the ignition off. Some other ideas: Aftermarket radio, gizmo plugged into the OBD port. Also visor/vanity lights or cargo lights hang off the same fuse in the later models.

 

98.

The radio is aftermarket but it has its own fuse. I couldn't find any other vanity lights or visor lights that even exist, much less be on. The cargo lights are on the fuse too but I verified those were not it. When I open the door they kick on and the draw goes from a half amp to about 2.5.
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The connection to the radio is not for powering it but for the clock/memory. It's a fairly thin pink wire, where does that go now ?

 

Dang it. I don't know. It's aftermarket but I didn't install and I can't find the little pull tabs to pull the stereo out so I may have to take the dash apart.

 

Glove box light? Ashtray light? Underhood lite??

 

Underhood is unplugged. I had someone hold the glove box button in manually. I think I tested the ashtray light but will give it another look.

 

Hook the meter up and start pulling fuses until the draw stops then you found it. If you did this and still can't find it try disconnecting the power cable on the alternator. A bad diode in the alternator could be causing it.

 

I've done this and traced it back to the iod fuse. Problem is there are a dozen different things behind this fuse and that is where I'm stuck. I've checked everything I can find and still seeing the draw.

 

What year is your truck?