Would leaving the ignition on cause damage to the coil?
 

I don't think so, as it shouldn't be any different than running the car for an extended period as far as the coil is concerned. I left my ignition on overnight (killed my two-week old 6V Optima), and now the car seems harder starting when warm. Spark is orange, not blue. Swapped condensers, no change. Set point gap and filed the points. Just wondering if it is possible to damage the coil by leaving it on for hours.

Thanks for any input!

Re: Would leaving the ignition on cause damage to the coil?
 

Yep, it will

Re: Would leaving the ignition on cause damage to the coil?
 

Does it burn up the insulation in the coil & cause an internal short? I ordered a new coil...may take this one apart with my daughters after I get the new one.

I normally leave the key in the ignition, will start putting it somewhere else.

Re: Would leaving the ignition on cause damage to the coil?
 

If you have an original pop-out it could burn it out also, Could.

Re: Would leaving the ignition on cause damage to the coil?
 

Only if the points are closed and current is passing thru them.

Re: Would leaving the ignition on cause damage to the coil?
 

If you want to open the old one just remember that some used PCB's and that is bad stuff. Better to not include others.

Re: Would leaving the ignition on cause damage to the coil?
 

I've seen a coil burned up in 30 minutes, when the key was left on.
It draws 4 amps with the engine stopped, but only uses 1 to 1 1/2 amps when the engine is running.

Re: Would leaving the ignition on cause damage to the coil?
 

Good point, thank you.

Re: Would leaving the ignition on cause damage to the coil?
 

Also with a Petronix it is a big NONO!

Re: Would leaving the ignition on cause damage to the coil?
 

As to what to do with your key when not driving, I hang mine on the throttle rod, as it is in the up position and the key ring slides on the nicely. The key is readily accessible from there.

Re: Would leaving the ignition on cause damage to the coil?
 

POCKETS are made for KEYS/CHANGE/SMALL PARTS/ETC.
Bill Cargopants

Re: Would leaving the ignition on cause damage to the coil?
 

That's why I like having the cut off switch, its habit forming to shut that, and the fuel every time I park the car.

Re: Would leaving the ignition on cause damage to the coil?
 

Isn't the key a cut-off switch?

Re: Would leaving the ignition on cause damage to the coil?
 

Not really, only cuts power to the ignition system.

A true cut-off switch breaks all connection with the battery.

Re: Would leaving the ignition on cause damage to the coil?
 

A bit off the subject but I had a short in my ignition system and this caused the coil to heat up quickly. So another thing that can mess up a coil. But this is also a way to tell if you have a short (assuming it did not blow a fuse) in your system. If coil is warm, find the short.

Re: Would leaving the ignition on cause damage to the coil?
 

If the points are closed. Sounds like your were. If the points were open ( high point of the cam) you would be lucky.

Agree with Tom. Depending on the health of the coil you can burn it up. It's constant power to the coil which would make it heat up. Like Tom said the constant daw is more than the intermittent of the properly operating ignition circuit.
It probably damaged the points as well. I would install a new set of points, test the coil, ( should be load checked and have at least a 12KV output).

If suspicious try another good known coil. I'm able to test my own coils, condensers, etc so I know what they are doing. Most folks don't have that option and I understand that so that's why I say I would try another known good coil. That one is probably damaged to some extent.
Larry Shepard
Larry

Re: Would leaving the ignition on cause damage to the coil?
 

Some of my friends avoid this possibility by hanging the keys on the gas shut-off handle. Also avoids memory lapses with the shut-off.

Re: Would leaving the ignition on cause damage to the coil?
 

Why tempt fate by leaving the keys in the vehicle?

Re: Would leaving the ignition on cause damage to the coil?
 

Agreed! Found this out the hard way. My starter failed when attempting a start and with the key off kept cranking until I grabbed a wrench and disconnected it! Needless to say I installed a kill switch along with the repaired starter.

Re: Would leaving the ignition on cause damage to the coil?
 

I installed a new Petronix coil and the car is running great again. Has a huge blue spark vs. a 1/8” orange spark. Really mad at myself for ruining the old coil...it has “Made In USA” on the bottom. Probably 40 years old or better.

I can pull the coil wire off the distributor and the wire arcs to the distributor near 1/2”, maybe more, and the engine keeps running. Was a good illustration of how it works for my daughters.

I’m going to make this my new habit. It’ll keep me from trying to start before turning the gas on too.