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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: levisjohnson on July 14, 2011, 08:06:14 am

Title: Truck almost caught on fire.
Post by: levisjohnson on July 14, 2011, 08:06:14 am

Previous owner had a push button for the glow plugs.  Yesterday when I hit the button, smoke was boiling from under the hood and under the dash.  The insulation has completely burned off one of the wires before I could find where it had grounded.  The button had a lead going to each side of the relay.

So no I can't get the glow plug light to come on and I tried to jump the relay with a jumper and still nothing.

My question is, do you think it fried the relay? If not where should I start troubleshooting (can not be with 2 vehicles for too long)

Thanks guys!
Levis

Title: Re: Truck almost caught on fire.
Post by: jaredts on July 15, 2011, 09:19:47 am

Relays are easy to test.  I would start there if its easy to get to.  If you don't know how to test one look it up on the internet, just a meter or test light with some jumpers is all that is needed (meter's better for this).

Title: Re: Truck almost caught on fire.
Post by: levisjohnson on July 15, 2011, 12:57:44 pm

I tested the relay with a test light this morning and it was bad.  I bought the replacement last night but was too tired to deal with it.  Anyways, I traced the hot lead all the way back to the battery and found a mess.  The fusible link was gone and good thing or it would have caught the whole thing on fire.  The wire from the alternator to the battery had the insulation cooked off but was still in tact. 

I just can not figure out what caused the hard ground unless it was a combination of a bad relay and a ground short.

Title: Re: Truck almost caught on fire.
Post by: VileZambonie on July 15, 2011, 08:24:44 pm

Circuit protection!

Title: Re: Truck almost caught on fire.
Post by: levisjohnson on July 17, 2011, 05:24:57 pm

Quote from: VileZambonie on July 15, 2011, 08:24:44 pm

Circuit protection!

Doing that Now on the fix.