I got some time to trouble shoot and here is where I am.

I inspected the wiring harness and found a bare place on the cloth covered resistance wire that goes to the run side of the starter. I verified the wiring on the solenoid and coil was correct, I then put a heat shrink tube over the bare wire. I’m currently getting about 7.5 volts at the positive side of the coil with the key on and 13.5 volts with the engine running. I know this is too much voltage. I have tried a different coil condenser, just not sure where to go next.
KC

 

There should be no resistance wire coming from the starter, none at all. The only resistance wire should be coming out of your firewall to the coil.

the wire from the starter to your coil should read zero with engine running. If not, the mechanism in the starter solenoid isn’t disconnecting power from that wire which is designed for starting only.

please tell me you’ve measured the output of the wire from solenoid to coil with engine running? If not zero, thats a problem.

Any sparkies out there to verify what I’m saying is sound? I’m happy to be corrected.

 

I assumed the cloth covered resistance wire at the firewall comes from the run side of the starter solenoid? I measured the voltage at the positive coil side with everything wired up. Start, run wire and condenser on the coil positive side and the distributor wire on the negative coil post.
KC

 

No they are two seperate wires. Resistance wire comes from fuse box. Other wire comes from starter solenoid. The starter solenoid wire allows full voltage for starting. The Resistance wire from fire walk allows your points to survive longer by supplying lower voltage when running. You have to do what I’ve said and test at the starter. It must be zero when the car is running. Check my posts for instructions. If you don’t check that the full voltage from starter is zero when car is running, you’ll continue to burn your points into oblivion!!!!!!!!!!!🔥

 

Omega, I’ll get those voltages checked and post back. Looks like I’m going to be out of town for a bit though.
Thanks!

 

For some reason your voltages are reversed.
How original is your car?
It almost sounds like the resistor wire, that goes to the junction box, was replaced with a normal one. And the one from the starter was replaced with a resistor wire.
I just can't fathom how you could get those voltages otherwise.

Be forewarned that there is no obvious resistor. It is just "X" length of small diameter wire that restricts flow (Amps) causing the delivered voltage to drop. I do not know if there is anything special about the copper in the wire, or not, or just small.
So you must check it with the coil in use and engine running to get some flow. Just hook up one of those 2 wires at a time and test Voltage. (Cover the end of the other with tape so it does not short on anything. Blue tape works well.)

It gets very confusing if you use a multi-meter / ohmeter to measure resistance. Almost no one knows what the resistances should be. A point coil has a 1.3 ohm spec. 67s and older used real ceramic resistor blocks, that were easy to spot, on the firewall, but not 68 up. The resistor wire is available from many places, is available in a specific length, and wire diameter. IIRC, from the factory there is a large rubber cylinder covering the junction between that and the normal wire. These must be removed to run an HEI, so many of them got removed over the years. There are several of the "junctions" around the starter also because there are several fusible links down there, on wires that are always hot, and have no other fuse.

Here is part of a thread with more specifics:
<snip> The normal resistance of a short 2' length of copper small gauge wire should be less than 1 ohm. U can buy a $15 multimeter at home Depot to measure this resistance and just read the instructions if needed. But resistor wire will have a couple of ohms per foot to reduce coil voltage down to about 9Vdc for normal operation. My best guess for coil current is 1 amp, then 12V battery voltage minus 9V normal operating means the wire drops 3V. So 3V divided by 1 amp = 3 ohms resistance - but resistance would be more/higher for lower current/amperage draw. <snip>
and
<snip> The stock resistor wire is a double coated silver conductor wire. The silver strands are the resistor, number of strands vs length make for the resistance value. this wire on a GM product is about 7-1/2 feet long and has a resistance value of 1.80 ohms. These wires are two coated, regular black plastic coating insulation under another plastic coating, white, with a "woven cloth" insulation appearance.<snip>


Best of luck testing! Something is definately off.
These wires break with age, and could have been replaced, even improperly.

 

I checked the wiring harness again and nothing looks spliced, it is an original harness.

I may have confused a few responders with the terminology. I do understand there isn’t a resistor associated with resistance wire and none has been added. My next step is to remove one wire at a time and check voltage on them. I’m a little confused and assume both wires need to be on the positive post to start but can be removed one at a time to test? The car should stop if the resistance wire is removed?
KC

 

The car won’t stop if you remove one at a time. It’s important that when it is running, only the resistance wire is live supplying its 7ish volts. That wire should be the one that comes from the fire wall fuse box. Yes both to +ve terminal. Still check the output of the other one at the solenoid with car running. Set 20v DC and test between the ouput terminal and case of the starter. Should be zero.

 

I understand the post but how can you get to the starter solenoid to test with the starter on the car? I had to pull the starter to even see the solenoid and verify it was wired correct.
KC

 

You just lay on your back and reach in behind the front wheel. Alternatively with it disconnected from coil and engine running, run the meter between the end and ground ie the bottom of the distributor or chassis.

 

The first wire pictured (says resistant wire on it) has about 7.5 volts with the key on and about 13.7 with the engine running. It appears to be original to the car. The engine will not run with this wire removed.

The second wire looks like it comes from the starter and doesn’t have any voltage with the key on or with the engine running. I’m stumped, what do you guys think?
KC

 

Ok something totally wrong. Your wiring is up the pooh. First wire (resistance wire) has correct voltage with car off. Should have SAME voltage with car running. Just confirming it comes from the firewall.

I don’t understand how it could read full voltage with engine running. Were there any another wires connected to the coil when you took this measurement with engine running?

The other wire from the starter, what does it read while disconnected and engine running?

Surely in this great group we have some electrical gurus??

If I lived in the USA and was in your town, I’d get over and fix it myself but I’m stuck in the Republic Congo of New Zealand.

next stop an auto electrician I think.

 

There were no other wires connected. No voltage read on the second wire with the engine running or no. I’m going to re visit the wiring at the starter. Here is a current picture of how it’s wired. The heavier wire is on the (S) and the lighter gauge wire is on (R).

 

I pulled the starter back off to verify the wire color. It appears that both wires are pink, maybe faded red? Maybe someone can identify by the wire gauge? One is several gauges heavier than the other. Just need help knowing which goes to start (S) and (R).
KC

 

Wiring diagram in post 139 says heavier 12 ga wire is purple and goes to the S terminal.

 

Thanks Leigh, that’s how I had it wired.

 

I dropped the starter today and checked the voltage on the S and R wires. Neither wire had voltage with the key off, the smaller gauge wire had 6.7 volts with the key on and the larger gauge had O.
KC

 

Just reading your post again (Sorry I was preoccupied when I initially read it doing three things at once), the wire from starter is operating correctly being zero with engine running.

The resistance wire is mostly doing the correct thing reading lower voltage with ignition on.

The car dying when you remove the resistance wire is good! That verifies the starter is supplying zero with engine running. That is correct.

only thing that appears wrong to me is the coil reading full voltage with car running. You need to ask an auto electrician if the coil should read full voltage on a ballast resistor ignition system with engine running or should it read 7ish volts.

 

I would think you have voltage back feeding from somewhere . The small wire from the starter should be zero if the starter is not engaged (the purple start wire energized) .you can disconnect the small wire at the starter and the other end of the wire at the coil and see if there's any power on it . I believe that those are the only connections for that wire . You have 7.5 volts at the coil engine off and 13.5 running . The resistance wire doesn't reduce the voltage to 7.5 volts it's a percentage . Could you have higher voltage from the alternator be raising the final voltage at the coil ? If your inputting 18 volts say , what would your voltage be at the coil ?

 

just another thought . Could it be backfeeding the coil through the starter solenoid ? the 6.5 volts you see at the solenoid is the voltage you're applying to the coil through the resistor wire . It's been a while since I had a solenoid apart but it makes a physical connection to send 12 volts to the coil when cranking .