Coil problems

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Sep 1, 2016 | 06:20 PM

MARC

Thread Starter

Tuned

Joined: Sep 1999

Posts: 436

Likes: 32

From: Sonoita

Coil problems

59 f100 with y block. Petronix ignition no ballast resistor. Fried 2 pertronix coils. Switched to resistor coil from Napa, still fried. Switched to non resistor coil and ballast resistor with same pertronix ignition. Have cooked 2 more coils. Only abnormal wiring is cutout switch on hot side of coil to kill power. Only use switch after truck off (extra anti theft device). Could this be dropping voltage too much to fry coils?
Any input and insight is appreciated
Thanks, Marc

Sep 1, 2016 | 07:40 PM

3414

Elder User

Joined: Jun 2008

Posts: 693

Likes: 6

From: N E Ohio

Usually it takes too high voltage to fry a coil. You might want to use a voltmeter to check the actual voltage at the coil terminal with the ignition on, engine not running, ignition unit triggered. From what I recall should be right around 8 volts. Also check running, and it should be zero with key off.

Sep 1, 2016 | 07:42 PM

hiball3985

Logistics Pro

Joined: Mar 2005

Posts: 3,771

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From: tujunga, calif

How long does it run before the coils quit? I'm not sure low voltage would cause that problem but to high might. Have you checked the voltage at the coil?

Sep 1, 2016 | 07:55 PM

MARC

Thread Starter

Tuned

Joined: Sep 1999

Posts: 436

Likes: 32

From: Sonoita

Don't know if heat from intake is frying it. Coil and bracket bolts are burning hot

Sep 1, 2016 | 08:03 PM

Tedster9

Post Fiend

Joined: Apr 2002

Posts: 19,311

Likes: 97

From: Waterloo, Iowa

Are you running an alternator or generator? What is the running voltage?

I've run a stock generator with pertronix flamethrower, Ignitor and bypassed resistor wire for years and years, but I don't live in Tucson, Arizona either. Millions of cars ran the coils sideways on the intake like the Y without complaint, but you could try mounting the coil vertically on the firewall.

One thing that's important when installing a coil horizontal (I guess) is that the terminals should be oriented horizontal as well, not vertical. Something about the way the cooling oil is distributed or somesuch.

http://www.pertronix.com/support/tips/

Note the part about not exceeding 8 amps total.

Sep 1, 2016 | 11:58 PM

oldbleu

More Turbo

Joined: Aug 2008

Posts: 693

Likes: 18

From: Atascadero, CA

Maybe a call to the Pertronix tech folks would be of value. It seems that their distributor unit is about the only thing that hasn't been replaced. Maybe there is some bad ju-ju in that part?

Dec 4, 2016 | 08:20 AM

MARC

Thread Starter

Tuned

Joined: Sep 1999

Posts: 436

Likes: 32

From: Sonoita

May have solved coil issue. If I direct wire coil to battery, and use remote start switch it fires right up. Bought new ignition switch. When I went to install it, I found that (I) had wired the ignition wire to the coil routed thru the acc position on switch. Rewired correctly, now at 150 miles later, no problems yet. And I now have a spare ignition switch. Duh!!