Author Topic: Smoking Wire  (Read 2071 times)

Offline micah123456789

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Smoking Wire
« on: March 28, 2015, 04:23:26 pm »
87 Silverado 4x4 TBI.  The truck cranked for about a half-second and then all of a sudden cut out.  Now no crank, but headlights, dome light, radio still have power.  Battery has 12.7 volts.  When I held the ignition key in the start position for more than a second or two, I noticed some smoke coming from under the hood.  Turns out it was coming from a wire on the firewall junction block just next to the brake cylinder.  The wire that was smoking goes towards the drivers side and into the dash around where the fuse box is on the inside.  It appears to have a fusible link on it near the junction block, but the link didn't blow.  The wire just gets really hot and the insulation burns off.

I'm no expert, but from what I understand, the purple wire on the starter solenoid gets + voltage when you turn the key forward.  Is that right?  I took an ohm meter and checked this wire to ground and sure enough it's grounded, but it's not the wire, it's the actual terminal on the solenoid that has continuity to the frame.  When the wire is disconnected from this terminal it's not grounded.  Is this a bad solenoid?

Offline VileZambonie

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Re: Smoking Wire
« Reply #1 on: March 28, 2015, 04:28:33 pm »
You can't check continuity through a component and say it is shorted. A solenoid needs a path to ground to work. In order for it to function you are bringing B+ to the terminal and the voltage is then dropped across the load.

Check your wires around the starter, alternator etc and ensure none of them are touching ground or have burned through insulation. Did you add any electronics recently? Check those as well before you replace the fusible link.
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