OK, I'm stumped

[Sixer]

R/T has the points back in, ballast in, etc. I get 10-11 volts at the coil key on, engine not running. Engine running, full voltage, as in 14 plus. Alt has dual field connection, one is connected, one isn't-charges fine. VR128 regulator. Where the hell are all the volts coming from at the coil? Has to be bypassing the resistor and feeding through the starting voltage wire, but wtf? Oh, R/T is 67, auto, wiring looks to be stock with no weird stuff.

 

[69Bee]

A normal charging system will charge between 14.5v to 15.2v, depending on temperature, with the motor running.

 

[Sixer]

A normal charging system will charge between 14.5v to 15.2v, depending on temperature, with the motor running.

Right. Voltmeter shows 12.8 at coil positive, 8.86 at negative with engine running. So resistor is working, just not down to the 9 volts or so I was expecting. Earlier volt readings were from quickie charge tester. Still seems high, coil gets pretty toasty pretty quick.

 

[69Bee]

Yea, coils do get hot. With your measurements, you have a voltage drop of 3.94v and I measured two coils I have here at 1.8 ohms across the primary. Doing the math:

3.94Volts / 1.8 Ohms = 2.19 Amps

That is alot of current, and it gets hot. Anyway, you won't burn out the coil even at 15v, so the more you have available to the coil, the hotter the secondary will be. It is just fine what you are seeing.

 

[PDFROGMAN]

Yea, coils do get hot. With your measurements, you have a voltage drop of 3.94v and I measured two coils I have here at 1.8 ohms across the primary. Doing the math:

3.94Volts / 1.8 Ohms = 2.19 Amps

That is alot of current, and it gets hot. Anyway, you won't burn out the coil even at 15v, so the more you have available to the coil, the hotter the secondary will be. It is just fine what you are seeing.

at 15V you will burn the points out

 

[Sixer]

at 15V you will burn the points out

And that's what I'm afraid of. However, the neg side of coil is 8.8 volts, the points can handle that. Been a long time since I dealt with points and their issues, if any. For what it's worth, I had installed, and subsequently removed a Pertronix Ign III, which was nothing but trouble for me from the get go. Wouldn't fit the vac advance in the distributor, once I found a adv that worked, car would never time right, needed 23 degrees to idle, which gave me a total of 43 degrees! Tried ported vac, unported vac, retarded, every combo in the book-keep in mind I haven't limited total advance, hence the mega number, but still. Pertronix support had no clue, and did not respond to 3 emails. Am looking to put in the complete Mopar electronic system, at least that should work........

 

[Ron 73]

It almost sounds like the ballast resister is working backwards, key on run it should say about 7 and in cranking should be 12 and reverts back to the 7 when the car starts and in run position, just a suggestion but could you maybe have a bad ballast resister..

 

[snakeoil24]

ballast resistor is either good or bad. Lower volts means oxidation in resistor feeds. Did you clean all grounds?

 

[PDFROGMAN]

has anyone done any harness work to this car?
when you crank the motor the ballast resistor is by passed and 12V is sent to the coil. once the key is released to the "run " position current to the coil run through the ballast resistor feeding the coil +/- 7.5V so that you dont burn the points out.

 

[Sixer]

No harness work I can see. I did some, to repair a severed Brown wire at the bulkhead connect-the very one that feeds full system volts to the coil at startup. Explains why R/T was such a hard starter-wire was frayed and finally broke at the back of the connector-with the repair, and a new mini-starter combustion is instant. The points see the neg side of the coil, so in this case that means 8.8 volts, which should be well within their capacity. In my first post, I had done a quick volt check with a charge tester, which has 5 leds each with a volt rating-8,11,12.5,13,14. When I used it at the coil it showed way high-14 was lit. With a volt meter however, it shows 12.8, with system at 14 and change-so resistor is functional (at first suspected a back feed bypassing the resistor and sending full volts to coil constantly), so my initial post was based on faulty info, and written in haste. Just shows that the coil doesn't get 9 volts, at least in this case, but the points only see 8-9 volts, which is how it should be. All is well in R/T land. Thanks for all the replies!