Can A Car Run With Coil Wired In Reverse?

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.

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.

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

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.

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.

Yes but should be down on power.

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.

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.