Coil Wired Backwards??????? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**DANTIP** · 02-11-2009, 09:42 PM

Just the primary connections on my ignition coil were wired backwards. Does anyone know what the potential consequences could be? Everything worked (temp gauge always read high), engine ran.

+ had the black wire leading to the distributor and brown tach wire.
- had the yellow ignition wire and black wire leading to the suppressor.

**Boog** · 02-11-2009, 10:26 PM

I don't know of any negative effects of running one wired backwards. I bought one many years ago that was wired backwards and ran it for a couple of yrs before finally doing a tune up and found it. Switched it back and it ran the same as before.

**VetteVet** · 02-11-2009, 10:41 PM

The primary windings in the coil and the secondary windings are both connected to the positive terminal. If the coil polarity is reversed then spark degradation occurs. This means a weaker spark and poor ignition. it also causes the coil to overheat and usually the center ignition terminal will crack. If you haven't been running it too long then just reverse the connections and no harm will be done.

02-11-2009, 09:42 PM	#1
DANTIP Registered User Join Date: Sep 2001 Location: Fort Wayne, Indiana, USA Posts: 1,882	Coil Wired Backwards??????? Just the primary connections on my ignition coil were wired backwards. Does anyone know what the potential consequences could be? Everything worked (temp gauge always read high), engine ran. + had the black wire leading to the distributor and brown tach wire. - had the yellow ignition wire and black wire leading to the suppressor.

02-11-2009, 10:26 PM	#2
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 13,136	Re: Coil Wired Backwards??????? I don't know of any negative effects of running one wired backwards. I bought one many years ago that was wired backwards and ran it for a couple of yrs before finally doing a tune up and found it. Switched it back and it ran the same as before. __________________ 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

02-11-2009, 10:41 PM	#3
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,709	Re: Coil Wired Backwards??????? The primary windings in the coil and the secondary windings are both connected to the positive terminal. If the coil polarity is reversed then spark degradation occurs. This means a weaker spark and poor ignition. it also causes the coil to overheat and usually the center ignition terminal will crack. If you haven't been running it too long then just reverse the connections and no harm will be done. __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.



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