HELP! Coil Blew UP!!! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

chevys2die4 · 08-08-2009, 12:03 PM

Well I finally got to the point of my restoration that I could drive (move) my 68 project in and out of my shop and then...I came into the shop the next morning and found oil all over engine and floor. I then found the coil had blew the post out and the wire to the dist. was toast!
A little back ground 1968 shortbed C10 396 Auto., points dist. all new everything full restoration with all wiring etc. anyone ever had this or heard of this happen? No the key was not left on, Truck had been running for months before this. I have know installed a pertronix ignitor and mathing coil but have not tested or started it yet until I can get some feed back from the board? I don't want to fry it! My strong point is not electrical but I feel confidant wiring is correct and no shorts or grounding issues I can find? HELP?

**Boog** · 08-08-2009, 12:20 PM

As far as I know the only way this can happen is if there is power going to the coil. There shouldn't be with the key off.

jeffspower · 08-08-2009, 12:35 PM

The points were closed while power was applied to the coil + post for a long time, overloading the wire, overheating the coil, expanding the oil & "popping" the top from expansion with nowhere to go.

It's caused by leaving the key on- but yours wasn't on. So power must have been coming from somewhere else- but that would mean the key wouldn't kill the engine

cdowns · 08-08-2009, 12:38 PM

also longterm use without a resistor circuit will cause this to happen

chevys2die4 · 08-08-2009, 12:48 PM

Quote:

Originally Posted by cdowns

also longterm use without a resistor circuit will cause this to happen

This might make sense? I need to check voltage to see if new harness may have not had a resistor wire (for elec ignition). Does this make since?

chevys2die4 · 08-08-2009, 12:54 PM

Quote:

Originally Posted by jeffspower

The points were closed while power was applied to the coil + post for a long time, overloading the wire, overheating the coil, expanding the oil & "popping" the top from expansion with nowhere to go.

It's caused by leaving the key on- but yours wasn't on. So power must have been coming from somewhere else- but that would mean the key wouldn't kill the engine

Thanks for putting it in terms I can understand! I will check this out, thanks all for your quick response

68gmsee · 08-08-2009, 01:31 PM

If you had a short in the starter solenoid, you may have fed back voltage from there??? It may be worth taking a look at that.

Look at the faq for a wiring diagram...

mclairmo · 08-10-2009, 07:34 PM

IIRC a Pertronix uses the stock resistor. Make sure to feed it with the proper voltage. Don't put 12 volts to it if it needs less.

chevys2die4 · 08-16-2009, 08:04 AM

Just to update those who replied. I installed new Pertronix in the distributer and a new matching coil. There is a resistor wire in the new harness, so I left it in. I believe the solinoid was shorting so I installed a new one, fired right up and I am back in buisness. Thanks again for all your help!!!

08-08-2009, 12:03 PM	#1
chevys2die4 Junior Member Join Date: Aug 2005 Location: Bryan,OH Posts: 157	HELP! Coil Blew UP!!! Well I finally got to the point of my restoration that I could drive (move) my 68 project in and out of my shop and then...I came into the shop the next morning and found oil all over engine and floor. I then found the coil had blew the post out and the wire to the dist. was toast! A little back ground 1968 shortbed C10 396 Auto., points dist. all new everything full restoration with all wiring etc. anyone ever had this or heard of this happen? No the key was not left on, Truck had been running for months before this. I have know installed a pertronix ignitor and mathing coil but have not tested or started it yet until I can get some feed back from the board? I don't want to fry it! My strong point is not electrical but I feel confidant wiring is correct and no shorts or grounding issues I can find? HELP? Attached Images __________________ 68 SB 396 72 SB CHEYENNE 402 04 Silverado SS

08-08-2009, 12:20 PM	#2
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 13,116	Re: HELP! Coil Blew UP!!! As far as I know the only way this can happen is if there is power going to the coil. There shouldn't be with the key off. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

08-08-2009, 12:35 PM	#3
jeffspower Well, Whoop-dee-do! Join Date: Mar 2003 Location: Easton, Mo. pop.- me & scarcely a few others Posts: 2,302	Re: HELP! Coil Blew UP!!! The points were closed while power was applied to the coil + post for a long time, overloading the wire, overheating the coil, expanding the oil & "popping" the top from expansion with nowhere to go. It's caused by leaving the key on- but yours wasn't on. So power must have been coming from somewhere else- but that would mean the key wouldn't kill the engine __________________ '68 GMC shortbox 4x4 350/SM465/T221- bought it in '83 SOLD '72 K20 500 Cad/TH400/NP205 SOLD '92 Chevy 2500 6.5 mech TD 4L80E crusty daily driver '72 Monte Carlo... sweet low mile toy '11 Dodge Challenger IE 392 6spd... midlife car

08-08-2009, 12:38 PM	#4
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: HELP! Coil Blew UP!!! also longterm use without a resistor circuit will cause this to happen __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

08-08-2009, 01:31 PM	#7
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: HELP! Coil Blew UP!!! If you had a short in the starter solenoid, you may have fed back voltage from there??? It may be worth taking a look at that. Look at the faq for a wiring diagram...

08-10-2009, 07:34 PM	#8
mclairmo Registered User Join Date: Jan 2006 Location: Take Off Posts: 1,908	Re: HELP! Coil Blew UP!!! IIRC a Pertronix uses the stock resistor. Make sure to feed it with the proper voltage. Don't put 12 volts to it if it needs less.

08-16-2009, 08:04 AM	#9
chevys2die4 Junior Member Join Date: Aug 2005 Location: Bryan,OH Posts: 157	Re: HELP! Coil Blew UP!!! Just to update those who replied. I installed new Pertronix in the distributer and a new matching coil. There is a resistor wire in the new harness, so I left it in. I believe the solinoid was shorting so I installed a new one, fired right up and I am back in buisness. Thanks again for all your help!!! __________________ 68 SB 396 72 SB CHEYENNE 402 04 Silverado SS



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