Got some electrical ghosts. Where are the grounds in the interior? Dome lights blowing 15 amp fuse, 20 amp will turn the lights on but when they should be off they only dim. Thanks in advance for any help.

 

Per my 2001 manual, courtesy lights are grounded (turned on) through the courtesy lamp relay which is controlled by the BCM. Point of ground is ultimately G200 + G201, both of which come out of the wiring harness and ground to the firewall high above the brake pedal. Problems on ground side of bulbs will not blow the courtesy fuse.

Note that on 2001 the courtesy fuse also feeds the "inadvertent power relay" and if has a NP1 transfer case (3-button) the courtesy fuse also feeds the transfer case controls. Through the body relay block, the DIC and rear view mirror are also supplied with power. I can only assume yours is the same. I would look in these areas for problems.

I think you need to get an online subscription to AlldataDIY for your particular vehicle if you want to work on this problem. Easiest and cheapest way to get the correct factory wiring schematics and locations of wiring, grounds, modules, relays, and connectors for your vehicle. It's going to be something simple that may or may not be very difficult to figure out. If a 10a fuse blows each time you plug one in, then I would definitely focus on that in the diagnosis. Get a handful of fuses and look at the schematic. Unplug appropriate connectors to isolate potential shorts or excessive current draws from the fuse until you find exactly what is causing it. Start with big things like unplugging connector at the body relay - then if fuse survives, narrow it down to things on the other side of the body relay block. You do need to be able to read electrical schematics and locate the connectors, etc. This is where the factory info will be invaluable.

 

Same per 2000 factory service manual.

 

I don't want to sound like a broken record since I recently stated the same thing to another poster...but do you have an aftermarket stereo or components installed? The radio harness shares a circuit with the interior lights on a '98.