Ignition Coil

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   The ignition coil on my V8 American gets so hot you cannot touch it.  Is this normal?

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Bill Mitchell Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Jul/12/2011 Location: St Matthews, SC Status: Offline Points: 346	Post Options Post Reply Quote Bill Mitchell Report Post Thanks(0) Quote Reply Topic: Ignition Coil Posted: Sep/17/2014 at 2:52pm
	The ignition coil on my V8 American gets so hot you cannot touch it. Is this normal?
	Bill Mitchell

uncljohn Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Jan/03/2013 Location: Peoria AZ Status: Offline Points: 5394	Post Options Post Reply Quote uncljohn Report Post Thanks(0) Quote Reply Posted: Sep/17/2014 at 9:39pm
	Do you have the correct coil? Or do you know? If you hand crank the engine so that the points are closed and the ignition key in the on position and measure the voltage at the + terminal of the coil do you measure something in the order of about 6 Volts? If not, then there may be a problem with the source of the voltage applied to it. It should be coming through a ballast wire from the ignition switch and it is possible something is miss-wired. Assuming of course the coil you are talking about is supposed to be an OEM coil and the distributor is OEM also with a properly adjusted set of points. If that is not true, more information is needed.
	70 390 5spd Donohue 74 Hornet In restoration 76 Hornet, 5.7L Mercury Marine Power 80 Fuel Injected I6 Spirit 74 232 I-6, 4bbl, 270HL Isky Cam

Bill Mitchell Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Jul/12/2011 Location: St Matthews, SC Status: Offline Points: 346	Post Options Post Reply Quote Bill Mitchell Report Post Thanks(0) Quote Reply Posted: Sep/18/2014 at 1:12pm
	Thanks for the reply John. Nothing is original equipment. There is some kind of electronic module in the distributor and the coil is marked MSD. You might be right about the wiring. I don't remember seeing a ballast anywhere. The wiring on this car is like a rats nest. Someone has cut and spliced all over the place. I have a TSM and will sort it out. The car runs good but I had to set the timing with a vacuum gage. Timing mark wouldn't come up on the strobe light. Got a lot of things to figure out. Plenty of time, I'm only 75. Ha, ha.
	Bill Mitchell

uncljohn Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Jan/03/2013 Location: Peoria AZ Status: Offline Points: 5394	Post Options Post Reply Quote uncljohn Report Post Thanks(0) Quote Reply Posted: Sep/18/2014 at 1:28pm
	Well Bill, you got 3 years on me and I just got back from Starting my Hornet I seem to have been working for ever on with a year off to have quadruple bypass. Those were the years when people cobbed things in whether they were qualified or not. And it is now worse when some one who has cut their teeth on factory fuel injection and suddenly buys a vintage car from yesteryear and starts out even more clueless. The AMC cars had a ballast wire in them from the ignition switch, Chrysler used Ballast resistors and i am sure so did others, but AMC was a wire. And if it has an MSD coil on it and the car is a frankelectonics set up complete with wires dangling it very well could have had some form of an electronic ignition long since cobbed over. If that is the case than it is possible some one by passed the ballast wire if it originally had points and ran switched 12 vdc over to it. If since then some one has installed a points distributor and just hooked it up to the coil as it existed, than like I mentioned earlier, put a meter on the + side of the coil. And hand crank the engine until the points go through an open/closed cycle. With the points open you should see 12vdc on the plus (+)connection, when the points close you should see aprox. 1/2 battery depending on the resistance value of the coil and the resistance value of the ballast wire if used. If it stays at 12vdc the switch 12VD was connected and some where in your wiring harness is the wire that is connected to the ballast wire, if it has not been cut out. In general, the ballast resistance and the coil resistance were the same ohm reading leading to more or less one half battery voltage when read at the + terminal with the points closed. IF the parts are the right ones and they are hooked up correctly. If this actually is some form of MSD ignition which included installing some form of a module in the distributor, see if you can look up a model number on the internet and find out if it should be hooked up to the oem BALLAST WIRE or should have had switched 12 wired to it. Because if it is hooked or should be hooked up to the OEM ballast wire, then the voltage would have been less than 12 volts applied which is the nature of the beast. Edited by uncljohn - Sep/18/2014 at 1:34pm
	70 390 5spd Donohue 74 Hornet In restoration 76 Hornet, 5.7L Mercury Marine Power 80 Fuel Injected I6 Spirit 74 232 I-6, 4bbl, 270HL Isky Cam

Bill Mitchell Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Jul/12/2011 Location: St Matthews, SC Status: Offline Points: 346	Post Options Post Reply Quote Bill Mitchell Report Post Thanks(0) Quote Reply Posted: Sep/18/2014 at 1:52pm
	Glad to hear about the bypass surgery John. We wouldn't be talking right now if you hadn't had that done. Ha, ha. Thanks for your suggestions. The distributor has a module instead of points. The original ignition switch Is long gone in favor of another (?) So I have some looking to do. Getting under the dash is no easy task for me. Like I said the wiring is a mess. But this is my hobby of choice (old cars) and as long as you don't put a deadline on things they don't become a job.............
	Bill Mitchell

FSJunkie Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Jan/09/2011 Location: Flagstaff, AZ Status: Offline Points: 4742	Post Options Post Reply Quote FSJunkie Report Post Thanks(0) Quote Reply Posted: Sep/18/2014 at 3:04pm
	Bigger question would b if everything else metal on the engine is the same temperature. Infrared thermometers are awesome.
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Bill Mitchell Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Jul/12/2011 Location: St Matthews, SC Status: Offline Points: 346	Post Options Post Reply Quote Bill Mitchell Report Post Thanks(0) Quote Reply Posted: Sep/19/2014 at 3:49pm
	FS Junkie, only the coil is overheated(?). Engine is running good and at normal temperature about 180 degrees. Someone moved the coil to the driver side fender out of the air flow from the fan. Maybe it is normal to be hot. You cannot touch it without getting burned. I can check the temperature of the coil......
	Bill Mitchell

bigbad69 Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Jul/02/2007 Location: Ottawa, Ont. Status: Offline Points: 6668	Post Options Post Reply Quote bigbad69 Report Post Thanks(0) Quote Reply Posted: Sep/19/2014 at 5:33pm
	Even out of the air flow, it should not be getting so hot you can't touch it. Either it is not wired to its spec, or it is damaged. You did say the ignition is cobbled together, so find the manufacturer's specs for the coil and compare it with what you have driving it. If everything is in spec, the coil is bad.
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jeremy0711 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Dec/12/2008 Location: Southern IN Status: Offline Points: 1547	Post Options Post Reply Quote jeremy0711 Report Post Thanks(0) Quote Reply Posted: Sep/19/2014 at 6:57pm
	Where is the distributor tied into the coil at the "+" or "-" side. I think Chevy is wired as backwards. I wouldn't know as I never owned one but thought I read it somewhere.

RamblinMan Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Sep/26/2007 Location: Port Charlotte Status: Offline Points: 1237	Post Options Post Reply Quote RamblinMan Report Post Thanks(0) Quote Reply Posted: Sep/19/2014 at 8:14pm
	My 65 classic did not have a resistor wire, it had an actual resistor. You CAN get a coil with an internal resistor. I ran straight 12 volts to my non-resisted coil and it got so hot it failed. This was when it had the 232 in it and before I went to an HEI distributor. At the time I was running Pertronix with a factory type canister coil. The HEI coils take a full 12 volts.
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