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Can A Car Run With Coil Wired In Reverse? #83350
07/03/08 09:15 AM
07/03/08 09:15 AM
Joined: Jan 2003
Posts: 1,019
Eau Claire, WI
ResQ911 Offline OP
super gas
ResQ911  Offline OP
super gas

Joined: Jan 2003
Posts: 1,019
Eau Claire, WI
Realized today my coil wires are reversed.
The harness was cobbled up by the last guy and had red wire for neg and blue for pos.
I assumed red was for pos and hooked everything up.
Car ran but noticed error later and switched them to correct following wiring schematic.
I didn't think car would've run with wires reversed.
Now I am wondering if I might have fried anything.....it runs rough at idle now.
Thanks for any help.

Re: Can A Car Run With Coil Wired In Reverse? [Re: ResQ911] #83351
07/03/08 09:33 AM
07/03/08 09:33 AM
Joined: Jun 2003
Posts: 21,397
It's a dry heat
gtx6970 Offline
Too Many Posts
gtx6970  Offline
Too Many Posts

Joined: Jun 2003
Posts: 21,397
It's a dry heat
yes it wil run but if put on a scope the pattern will be upside down

Re: Can A Car Run With Coil Wired In Reverse? [Re: gtx6970] #83352
07/03/08 09:49 AM
07/03/08 09:49 AM
Joined: Jan 2003
Posts: 1,019
Eau Claire, WI
ResQ911 Offline OP
super gas
ResQ911  Offline OP
super gas

Joined: Jan 2003
Posts: 1,019
Eau Claire, WI
Was anything damaged by running it with wires reversed??
It seems to idle like crap now.
But smooths out off idle.
Any thoughts?

Re: Can A Car Run With Coil Wired In Reverse? [Re: ResQ911] #83353
07/03/08 09:53 AM
07/03/08 09:53 AM
Joined: Jun 2003
Posts: 21,397
It's a dry heat
gtx6970 Offline
Too Many Posts
gtx6970  Offline
Too Many Posts

Joined: Jun 2003
Posts: 21,397
It's a dry heat
Quote:

Will anything damaged by running it with wires reversed??
It seems to idle like crap now.
Smooths out off idle but starts nice.
Any thoughts?




As far as I know there's no real difference. I had a car several years back that came into the shop for a maintence tuneup with no running issues, he just wanted a tune up. When we hooked it up to the scope is when we noticed the pattern. I changed the wiring connections and never heard anything one way or the other

Re: Can A Car Run With Coil Wired In Reverse? [Re: gtx6970] #83354
07/03/08 10:31 AM
07/03/08 10:31 AM
Joined: Apr 2005
Posts: 2,222
Anderson, SC
resqguy Offline
top fuel
resqguy  Offline
top fuel

Joined: Apr 2005
Posts: 2,222
Anderson, SC
Many many years ago (1977) when I worked pumping gas, I had a guy come in with a Buick Skylark. He had just spent a pile of money on the motor and wasn't happy about how it was running. Since the station mechanic had left for the day I explained to the guy I could look at it but our shop minimum was $20. I put it on the scope (not bad for a kid that just pumps gas) and I noticed the coil wired wrong. I switched the wires and proceeded to check dwell and timing. I set everything and sent the guy on his way.

About an hour later he came back with a car full of his buddies. Now I'm thinking he is coming back for his $20. As they got closer I noticed they were in good spirits. Instead of wanting there money back they gave me a 6 pack and were recounting a few kill stories on the freeway.

I doubt the miswire will cause any damage. The effect is that your coil won't put out the voltage that it should. Your plugs will probably still get enough to fire so the car will run. If you have had set the timing with it wired wrong you should recheck everything after the correction.

Re: Can A Car Run With Coil Wired In Reverse? [Re: resqguy] #83355
07/03/08 10:33 AM
07/03/08 10:33 AM

A
Anonymous
Unregistered
Anonymous
Unregistered
A



This will not DAMAGE anything.

My mind isn't what it once was, but I believe you won't have the POWER you should have in your spark output.

Back "in the day" of breaker points, this would cause short point life, as I recall.

Re: Can A Car Run With Coil Wired In Reverse? #83356
07/03/08 11:03 AM
07/03/08 11:03 AM
Joined: Jan 2003
Posts: 32,916
Grand Prairie,Texas
stumpy Offline
I Win
stumpy  Offline
I Win

Joined: Jan 2003
Posts: 32,916
Grand Prairie,Texas
It just causes low plug fire voltage and won't do anything but foul plugs.

Re: Can A Car Run With Coil Wired In Reverse? [Re: stumpy] #83357
07/03/08 11:15 AM
07/03/08 11:15 AM
Joined: Jan 2003
Posts: 25,200
Upper Midwest
M
MoparforLife Offline
Too Many Posts
MoparforLife  Offline
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M

Joined: Jan 2003
Posts: 25,200
Upper Midwest
Quote:

It just causes low plug fire voltage and won't do anything but foul plugs.




Clean it, if it's Dirty. Oil it, if it Squeaks. But: Don't fix it, if it Works!
Re: Can A Car Run With Coil Wired In Reverse? [Re: ResQ911] #83358
07/03/08 12:19 PM
07/03/08 12:19 PM
Joined: Jan 2003
Posts: 8,144
Arkansas
340727dart Offline
master
340727dart  Offline
master

Joined: Jan 2003
Posts: 8,144
Arkansas
A couple weeks after I got my '71 Dart /6, I discovered the coil was wired bass-ackward.
The car started and ran OK but was definitely no speed demon.
There's no telling how long it was like that. The guy I bought it from really hacked up all the wiring.
It was only getting 14.6 mpg during that time. After I corrected the wiring the mileage increased to 17.8.
It's still no threat to any speed records but it runs better.


Your life is not my fault.
My life is none of your business.

Speech is free only if you agree with those in control.
Re: Can A Car Run With Coil Wired In Reverse? [Re: ResQ911] #83359
07/03/08 03:39 PM
07/03/08 03:39 PM
Joined: Apr 2004
Posts: 1,396
Mass
dgc333 Offline
pro stock
dgc333  Offline
pro stock

Joined: Apr 2004
Posts: 1,396
Mass
Electrically speaking there is no difference other than the reverse output others have mentioned seeing on a scope. When the primary windings are reversed the spark will jump from the side elctrode of the plug to the center compared to just the opposite when wired correctly.

The direction the spark jumps shouldn't make a difference either. Just look at all the 4cyl motorcyles with 2 coils and 4 cyl cars with a coil pack. In these applications one end of the secondary is connected to one cylinder and the other end is connected to the complimentry cylinder. So every time a pair of cylinders come to TDC both plugs fire one cylinder on the power and a wasted spark in the exhaust stroke of the other cylinder. In this type of application one plug fires from the center electrode to the ground electrode and the other from the ground to the center.


Dave Clement Pembroke, MA 03 PT Cruiser GT Turbo 99 Dakota SLT+ CC 4x4 68 Barracuda sport coupe http://home.comcast.net/~dgc333/
Re: Can A Car Run With Coil Wired In Reverse? [Re: ResQ911] #83360
07/03/08 04:19 PM
07/03/08 04:19 PM
Joined: Jan 2003
Posts: 12,405
Southern, Ca.
69DartGT Offline
moparts member
69DartGT  Offline
moparts member

Joined: Jan 2003
Posts: 12,405
Southern, Ca.
Yes but should be down on power.

Re: Can A Car Run With Coil Wired In Reverse? [Re: 69DartGT] #83361
07/03/08 04:24 PM
07/03/08 04:24 PM
Joined: Sep 2005
Posts: 12,481
Chino Valley
RodStRace Offline
I Live Here
RodStRace  Offline
I Live Here

Joined: Sep 2005
Posts: 12,481
Chino Valley

It should start and run, but be down on power, especially over 55-60 MPH.
Remember that most cars were positive ground until the 1950s.
IIRC, the coil saturation and collapse is better when wired correctly.

Re: Can A Car Run With Coil Wired In Reverse? [Re: ResQ911] #83362
07/03/08 04:33 PM
07/03/08 04:33 PM
Joined: Jul 2003
Posts: 3,374
Rancho Cordova, CA
Exit1965 Offline
master
Exit1965  Offline
master

Joined: Jul 2003
Posts: 3,374
Rancho Cordova, CA
I've run them in reverse before -- due to Accel's error on some instructions, and when I reversed them, it ran fine, didn't fry anything.







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