Hot Ballast Resistor

-
6

65dartman

Active Member
Joined
Nov 14, 2005
Messages
29
Reaction score
0
Location
Colorado
Gents, I just got my car running again and seem to have an electrical gremlin! Sometimes I have spark and sometimes I don't! I originally thought i had a bad ground on the ignition box, but I've taken care of that and still have a problem. The other day I went for a short drive, stopped at a stop sign , the car died and would not fire again. While checking all connections under the hood I burned my fingers when I touched the ballast resistor. We pulled it home let it sit until the next morning and it fired right up.? I do have electronic ignition and still have the old style alternator, I've been told your suppose to switch to the external regulator style if you switch to electronic ignition. Is this maybe my problem?

Thanks.
 
The ballast resistor will get hot, it is a resistor and that is why it is made out of ceramic and not plastic.

You can use the old style single field alternators but you are supposed to use the constant voltage regulators when converting to Mopar electronic ignition. I am using the old style alt with the constant voltage reg and Mopar electronic ignition and everything works fine. I would bet that you need to change your box it is most likely your problem. Since the resistor is getting hot it is resisting. If it was cold then it would mean no voltage was going thru.

Chuck
 
Well, not to argue with you, but I don't believe the resistor should get hot enough to burn you. This thing was hot enough to burn up itself (the Element) in my opinion. But I've never noticed how hot they get normally. What's involved with switching to the newer style regulator? Oh, and I have tried two different ignition boxes with the same issue. Thanks! :salute:
 
I bought the reg from Mopar Performance. One way the resistor could get hotter is if the wire on the other side was grounding. Since it happens with two different boxes and the resistor feeds the coil sounds like possibly the coil has an internal short. Could try a different coil.

Which resistor are you using?

Chuck
 
I believe the resistor is one that was listed for a mid 70's duster from a local auto parts store. I was kind of wondering about the coil myself, I'll try another coil and see what happens. Thanks for the idea's Chuck! I'll keep you updated.
 
If your ecu has gone bad and is is keeping the (-) side of the coil grounded all the time it is not suprising that the ballast resistor is getting very hot.

The electronic ignition in our cars works very much like a points system, that is, current is flowing through the coil the majority of the time and it is the disruption in current flow (points opening, ecu truning off) that cause the high voltage in the secondaries and subsequent spark.

Starting when cold then quiting when hot then restarting when cooled down is a classic symptom of a bad electronic control module.

You can pick up a new ecu module for less than $20 at Advance Auto or Autozone. Also, you can pick up a replacement voltage regulator that has solid state guts (in place of the mechanical guts) at the same time for about $10.
 
Check the ohm rating of the resistor you have.There are two different resistors with different ohm ratings.Had the same thing happen to me in my 65 when I put in a new new resistor.
 
It could also be the exciter, the little black block inside the distributor. I had one that cut out the ignition when it got hot and ran again when cooled off.

Terry
 
Ballast resistors will get hot, & you should also ALWAYS carry 2 new extras in your glove box at ALL times. They are known for causing no-start problems. I just bought 2 for my Coronet this weekend and they cost $3.79/ea.

A new ECU will not set you back much as dgc333 said. Do your self a favor and replace the ECU, VR, and go buy 3 ballast resistors. One for the car, and 2 for the glove box.
 
I had the same problem once. it turned out to be the coil. it had a crack in it and oned to got hot and expanded it would loose contact somehow. when it cooled off it would work again. put a new coil in and fixed the issue.
Jeff
 
I too had a problem just like yours. Mine was the wire going from the coil to the dist. It only had a couple of hairs that were not broke. Car would run fine for awhile then just die. Let it set for 15-20 minutes and it would start right back up. Fixed the wire and haven't had any problems with it since. Just another idea to look at.
 
I've seen cases where the same parts were replaced repeatedly and every time the vehicle would start and run. Owner paid for what he thought was a repair.
My actions depend on my mood, work load, etc.. So
I might replace stator, module, coil, etc.. once without looking at anything else. Just carry on or send it on with my fingers crossed. If the same fault reoccurs, that changes my mood. I'll dig deep. Check every wire and connector and find the root fault.
Ballast resistors do get blister your finger hot. That doesn't cause intermittent shut down. Resistance and resulting heat in other parts like wires and connectors will.
This includes those connections inside modules. I've seen them melt the gell coat off their backside and continue to operate intermittently.
 
You must log in or register to reply here.
-

Back
Top