cjmspartans
OBS Enthusiast
Hello everyone! I've got a bit of an issue that has me scratching my head. My 97' K2500 Burb blew the 30A "RR DEFOG" fuse under the hood, so I've been without the rear defogger for a few months. Otherwise, the truck has been running great aside from a interior door handle snapping again
What I (stupidly) did yesterday was replace the blown 30A RR DEFOG fuse with a good 30A fuse, just to see if the issue would reproduce its self, and oh boy did it! Turned the truck on, turned on the rear defogger (orange light came on... yay?)... and smoke started coming out from under the dash. Fantastic. Absolutely fantastic. Immediately removed the key and the 30A fuse. When I tried to remove the fuse, it was interesting because the plastic just melted and the fuse never popped. What this tells me is we have high resistance in the circuit, but it's not pulling 30+ amps to pop the fuse. For what it's worth, the rear passenger glass was warm but the drivers side glass was cold in the end. The Burb has barn doors, if that matters.
My big question here is, does anybody have wiring diagrams that they could share for this circuit? I've tried searching but my searching skills might not be that great. The truck still runs and everything else (that I can tell) works fine. No more smoke is coming from the dash after the fuse was removed. I need to test that these now crispy wires are indeed not energized with a test light or multimeter before I drive it around.
Additionally, does anyone have any insight into these rear defoggers? Is this type of event common if they fail? I don't have the slightest idea how these things work. I'd like to avoid bringing it to a shop because that sounds like a big bill, but I want to make sure that the wiring is at least safe. If I can safely drive it around with no rear defogger, that's fine. But I want to make sure there isn't any additional damage. I can already tell that the dash will need to come apart so I can check the wiring going back from the HVAC controls.
Here's some pictures for you guys:
The 30A fuse when I pulled it out of the fusebox. Yummy!
The destroyed purple wire that I assume runs to the back of the truck. Crispy!
The now crispy red wire coming out of the dash wiring harness that connects to the rear defogger switch on the HVAC controls. This is definitely going to be labor intensive or expensive. Or both. And yes, the copper is showing in those holes on the insulation. I'm assuming that damage was done when it started smoking.
What did I learn? When a fuse pops, it's for a reason. This was bad on my part but the problem likely would have occurred even if I brought it to a shop for diagnosis.
Very sad day for me. But hey, things happen. Hopefully someone here can provide some insight. Many thanks guys!
What I (stupidly) did yesterday was replace the blown 30A RR DEFOG fuse with a good 30A fuse, just to see if the issue would reproduce its self, and oh boy did it! Turned the truck on, turned on the rear defogger (orange light came on... yay?)... and smoke started coming out from under the dash. Fantastic. Absolutely fantastic. Immediately removed the key and the 30A fuse. When I tried to remove the fuse, it was interesting because the plastic just melted and the fuse never popped. What this tells me is we have high resistance in the circuit, but it's not pulling 30+ amps to pop the fuse. For what it's worth, the rear passenger glass was warm but the drivers side glass was cold in the end. The Burb has barn doors, if that matters.
My big question here is, does anybody have wiring diagrams that they could share for this circuit? I've tried searching but my searching skills might not be that great. The truck still runs and everything else (that I can tell) works fine. No more smoke is coming from the dash after the fuse was removed. I need to test that these now crispy wires are indeed not energized with a test light or multimeter before I drive it around.
Additionally, does anyone have any insight into these rear defoggers? Is this type of event common if they fail? I don't have the slightest idea how these things work. I'd like to avoid bringing it to a shop because that sounds like a big bill, but I want to make sure that the wiring is at least safe. If I can safely drive it around with no rear defogger, that's fine. But I want to make sure there isn't any additional damage. I can already tell that the dash will need to come apart so I can check the wiring going back from the HVAC controls.
Here's some pictures for you guys:
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The 30A fuse when I pulled it out of the fusebox. Yummy!
You must be registered for see images attach
The destroyed purple wire that I assume runs to the back of the truck. Crispy!
You must be registered for see images attach
The now crispy red wire coming out of the dash wiring harness that connects to the rear defogger switch on the HVAC controls. This is definitely going to be labor intensive or expensive. Or both. And yes, the copper is showing in those holes on the insulation. I'm assuming that damage was done when it started smoking.
What did I learn? When a fuse pops, it's for a reason. This was bad on my part but the problem likely would have occurred even if I brought it to a shop for diagnosis.
Very sad day for me. But hey, things happen. Hopefully someone here can provide some insight. Many thanks guys!