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Old 05-27-2005, 10:04 AM   #1
Scooter67
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hot underdash wires

With the fan running, I noticed a couple of the wires leading to the switch are hot to the touch. You can bear your fingers on them, so it's not like they're melting or nothing, just hot enough to make me wonder.

Is this normal? I'm an electrical dufus, in case you haven't guessed.
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Old 05-27-2005, 10:14 AM   #2
blazerparts
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might be a leak in one of your duct hose.........blowing hot air on the wires.
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Old 05-27-2005, 10:15 AM   #3
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Warm wires indicate high resistance. Clean up all of the surfaces on your ground for the fan motor. It is the bonding wire that leads from the case of the fan to the firewall. There is a resistor mounted in the heater box. I do not know what the ohm readings should be for it maybe someone else will...
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Old 05-27-2005, 10:22 AM   #4
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Also wires will heat up if the connectors are loose-make sure all slip on plugs are tight.
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Old 05-27-2005, 10:46 AM   #5
86swb
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I worry about stuff like that. This is why I keep a fire extingisher in my trucks. Just in case.
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Old 05-27-2005, 10:50 AM   #6
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Quote:
Originally Posted by 86swb
I worry about stuff like that. This is why I keep a fire extingisher in my trucks. Just in case.
Scares the crap outta me too! Now I'm afraid to run the A/C till I clean all the connections and check it out good.
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Old 05-27-2005, 10:52 AM   #7
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Are you sure you have the right fuse for those wires?
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Old 05-27-2005, 10:53 AM   #8
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The right fuse should blow if wires gets too hot.
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*1986 Chevy SWB Silverado
*1984 Chevy Longbed Silverado

New Kia Sportage (Wife's car and she loves it)

CHEVY, American made w/pride!


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Old 05-27-2005, 11:01 AM   #9
Scooter67
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Quote:
Originally Posted by 86swb
Are you sure you have the right fuse for those wires?
Can't say for sure. Guy who built the truck did a super job on everything and it's been working great for thousands of miles, so I'm assuming it's fused properly.

HOWEVER...you know what they say about assumptions.
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Old 05-27-2005, 11:04 AM   #10
chickenwing
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I'd check it out soon. My fan did not work when I first got the truck. When I pulled the fan switch connector it had 1 pin half melted off! Never figured out the cause, I was replacing the whole harness anyway.
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Old 05-27-2005, 11:08 AM   #11
86swb
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You sure do not want to have a fire and nothing to put it out with. You could just say to your nice truck.
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New Kia Sportage (Wife's car and she loves it)

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Old 05-27-2005, 11:17 AM   #12
barn9
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Not sure how accurate this is, but I was told once by a mechanic that the wires to the fan were notorious for over heating, and he said it was (in his opinion) because GM used to light of a guage wire for the application. When I had my dash all apart, I found mine were on the verge of burning, so I was concerned myself. He came over and replaced them with the appropriate sized wires, and I have never had any problems since. Like I said, it might have been just his opinion, but what he did seems to have been an improvement, and I feel a little more at ease when using the fan.
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Old 05-27-2005, 11:25 AM   #13
chickenwing
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Someone, maybe Putter, outlined going to a relay set-up for all of the fan speeds.
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