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Panel/Dome Circuit Problem

Kjake

2️⃣ Bronze
Tacoma3G Supporter
Joined
Dec 23, 2018
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Location
Upper Michigan
I was installing a set of Meso’s puddle lights and after running the wires from the doors to the a-pillar I disconnected the wiring connector in the a-pillar where the y-harness connects. I then plugged the y-harness in and reconnected the battery. I immediately saw smoke from under the dash and attempted to disconnect the y-harness but had already melted some wires. I never made it as far as connecting the wiring from the doors to the harness.

Confused about why the wires melted at first but eventually realized I had mistakenly swapped a 30 amp fuse with an adjacent 7.5 amp fuse at some point in the past.

Cant explain why installing the y-harness would have caused a short though. I’ve tested the harness and couldn’t find a problem with it. Prior to installing though, everything worked fine.

At this point I’m looking for help to understand what I’m experiencing. It actually seems to be two problems. One with the panel illumination and one with the dome light circuit. Currently the dome circuit is shorted to ground and I can’t seem to find where. I’ve checked it with the roof harness disconnected at the A-pillar and the dome wire appears To be grounded somewhere under the dash. Stranger fact is that the panel illumination circuit also appears to be shorted but only when the doors are closed. In other words, the panel illumination fuse blows immediately when the doors are closed but works fine as long as they’re open. I don’t understand why the panel illumination would be connected to the door switch or the dome circuit.

I‘d Like to try to solve this one problem at a time so if anybody can offer a suggestion on the panel light circuit, I’d sure appreciate it.
 
I was installing a set of Meso’s puddle lights and after running the wires from the doors to the a-pillar I disconnected the wiring connector in the a-pillar where the y-harness connects. I then plugged the y-harness in and reconnected the battery. I immediately saw smoke from under the dash and attempted to disconnect the y-harness but had already melted some wires. I never made it as far as connecting the wiring from the doors to the harness.

Confused about why the wires melted at first but eventually realized I had mistakenly swapped a 30 amp fuse with an adjacent 7.5 amp fuse at some point in the past.

Cant explain why installing the y-harness would have caused a short though. I’ve tested the harness and couldn’t find a problem with it. Prior to installing though, everything worked fine.

At this point I’m looking for help to understand what I’m experiencing. It actually seems to be two problems. One with the panel illumination and one with the dome light circuit. Currently the dome circuit is shorted to ground and I can’t seem to find where. I’ve checked it with the roof harness disconnected at the A-pillar and the dome wire appears To be grounded somewhere under the dash. Stranger fact is that the panel illumination circuit also appears to be shorted but only when the doors are closed. In other words, the panel illumination fuse blows immediately when the doors are closed but works fine as long as they’re open. I don’t understand why the panel illumination would be connected to the door switch or the dome circuit.

I‘d Like to try to solve this one problem at a time so if anybody can offer a suggestion on the panel light circuit, I’d sure appreciate it.
Hey bud by chance can you send me some photos of the harness that is an issue , thrbfuse that blew and a picture of the meso wiring please and thanks
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I can and I will but can’t until the weekend. Thanks so much for replying. The two fuses that are blown/blowing are the 7.5 amp dome fuse and the 5 amp panel fuse. When I can get the truck back in the garage I’ll send the pics. The wire that failed I believe to be the yellow dome light negative. I’m beginning to suspect the problem actually lies in the wiring to the roof or the overhead console. Basing that on some information from some posts elsewhere.

At any rate I’ll get you the pics as requested as soon as I can. Thanks again!!
 
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I can and I will but can’t until the weekend. Thanks so much for replying. The two fuses that are blown/blowing are the 7.5 amp dome fuse and the 5 amp panel fuse. When I can get the truck back in the garage I’ll send the pics. The wire that failed I believe to be the yellow dome light negative. I’m beginning to suspect the problem actually lies in the wiring to the roof or the overhead console. Basing that on some information from some posts elsewhere.

At any rate I’ll get you the pics as requested as soon as I can. Thanks again!!
Send me when you can, yellow wires are not negatives on toyota . Negative will be black or black/white
The dome light neg should be driver side kick panel
 
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