wire gets hot

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Jul 19, 2014 | 07:51 AM

jimmyz469

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wire gets hot

hi everyone. I replaced my ignition switch in my 78 f250. Once I got the switch out of the dash I noticed the socket that plugs into the back of the switch was melted some. The wires look fine. I cut the wires and crimped some quick disconnect clips on and connected them to the same spot on the new switch. One of the wires is now getting hot. This connection had two wires crimped together in the one spot and it looks like the factory wiring and connections so I did the same. is there to be some heat felt in the wire or is this bad? Im afraid that maybe what melted the socket in the first place.

Jul 19, 2014 | 08:25 AM

fmc400

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From: Austin, TX

That's not much to go off of. You're going to have to describe exactly which wire (color, specific location on the switch it starts, etc) is getting hot and under what conditions this happens. Pictures help too. Remember, I'm not there with you, so you're the eyes and ears.

Jul 19, 2014 | 10:05 AM

77&79F250

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From: S/W Missouri, Polk county

1. Follow fmc400 directions to the letter.
2. Well if it get hot enough to melt things, something for sure is not right.

Look over the eng compartment for a stray wire that is grounding out on something it is not suppose to. Melted wire bundle, anything touching the exhaust manifold or exhaust pipe?

Have you installed an after market stereo/amp/driving lights any accessories and maybe tapped power from a place you should not of?

Can you trace up stream of the switch (under the dash) and ck for a damaged/pinched wire bundle? It might involve lots of un-wrapping and cking each wire.

Look for previous owner wire mods, like fuses that are foil wrapped....

Jul 19, 2014 | 10:05 AM

77&79F250

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Oops fat fingered it, keep looking.

Jul 19, 2014 | 01:14 PM

jimmyz469

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sorry for the lack of info. The wire that gets hot is a red with blue stripe. about a 10-12 ga. wire. it gets hot right after I start the truck and gets hotter as I drive it. I have only driving around the block a few times I dont want to risk it getting hot enough to melt or catch fire. Once I shut the truck off it cools immediatly. The second wire that is connected in the same spot on the ignition switch is brown or orange in color and a smaller gage. It does not get warm to the touch. I traced the "hot" wire back and it goes into a big web of wires that are taped up together. Once the temps cool down outside I'll be able to spend a little more time chasing it back to see if I can find where it goes. Thanks for the help

Jul 19, 2014 | 01:31 PM

fmc400

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From: Austin, TX

RED with BLUE stripe is hot-in-START to the starter solenoid, and start-retard input of the ignition module. To be clear, when I say "hot," I mean "powered."

RED with BLUE stripe should not be shared with any other wire color. It's a dedicated signal. Something was put back together incorrectly.

Jul 19, 2014 | 06:34 PM

jimmyz469

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ok I feel stupid now, I went back out there and cleaned up the wires of all the dust and peeled a bunch of tape and could see some writing on the faulty wire. It says resistor do not cut or splice. it is red with a green stripe and green letters. I traced it back till it came to a little black rubber piece and coming out the other side it has a brown wire and a red wire with gold stripe. The red wire goes through the fire wall just above the fuse block and as best as I can tell goes into a 3 prong plug that is hanging there not plugged into anything under the hood next to the brake booster. I did find 2 wires under the dash dangling, some speaker wire that was only connected to the speaker, and an in line fuse that may have been a powered cable for the radio at one time. The more unwrapping I do the more loose wires I find. Im thinking it may be time for a new harness.