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on my 70 442 there is a resistor between the green and green/white wires going to the hei. it measures 147 ohms with it hooked up in the car. I have been reading that there was a resistor, or resistor wire which limited current to the points. Is that what this resistor is? If so, should it be removed? Also there is a yellow and a black wire stubbed out in this same piece of the harness.... Any ideas on those?
I am reading in the service manual (12-43) but not seeing any reference to HEI distributors...
That connector with the resistor is not your HEI power. I believe its your transcontrolled spark solenoid. You will not see a ref to an HEI in 1970 as there was none available. The yellow and black wire (if the yellow goes to the starter solenoid) is for the ignition. Although the black may be the resistance wire.
I’m gonna have to look at that yellow wire then. It’s been running with the green and green/white hooked up and the yellow taped up for two years .....
I finally broke down and had a shop help me get the carb tuned right and they told me the ignition was breaking up at high rpm. That’s the only reason I started reading about it and looking at it today
i just ordered a pigtail like the one in your picture. So I need 12v in start and run but not in accesory.... is that right?
There is a male spade terminal in your fuse box marked IGN, use a female spade and run a 12ga wire from there to your new connector batt terminal. The other terminal on the new HEI connector is for a tach.
Will do. I never paid much attention to it until now.
My distributor has another tach wire coming out of the base. Is there any difference In the two? I am hooked up to the bottom tach wire now and have had no issues.
I assume it is ok to leave this trans controlled spark connector unhooked.....
thanks guys. I’m looking forward to getting it right this week.
What other tach wire from the base? There should be only 2 terminals under the cap for the connector I listed above. The other connector on the cap should have 3 other wires that run into the distributor. I would look under the cap and make sure it was not modified (tach terminal removed) to run that wrong connector.
I will take it apart tomorrow but I did get a quick picture. There is a bundle of three wires from the base to the cap. Then there’s a green wire out of the base But I get what you are saying about the socket in cap being modified to fit the incorrect plug. But that green wire from the base runs to my tach
Last edited by mattking; Aug 20, 2018 at 05:22 PM.
I bet if you pull the cap off you will find a MSD ignition module. That wire is for traction control(???) I have no idea what that wire is suppose to do, or how it’s wired in to the ignition to control traction (maybe it’s used to pull timing in tow traction conditions?) That module is legal for certain dirt racing classes, it also has a rev limiter built in with no need for external ignition boxes. I had one of those modules on my 87 Cutlass with a 455. The car always ran well, just didn’t run as well as I thought it should have. When I sold the car to my brother in law he decided to make a race car out of it. He tore out the A/C, cruise, the console and floor shifter, the factory gauges, all the stuff I lovingly restored and rebuild to work again. He also replaced that module with a MSD 6AL box with future plans of nitrous and the ignition control stuff to control it. With no other changes to the engine the car ran MUCH better. Since then, I haven’t had much faith in the internal MSD modules. Just my opinion.
Ok, I installed the new pigtail. The car starts great and runs well. I will have to clear the driveway to get it on the road and see about driveability, but I am hopeful it will be better. Both green wires are tach output. I have the new pigtail going to the tach, and the wire from the base i put a cap on, so I can use it for my under-hood, tach dwell meter (non inductive).
My digital popping noise in the radio is gone so far, but it came and went, so time will tell.
The contacts in the HEI cap were bent a little from the wrong plug being installed.
This is the module, sorry was getting dark, I didn't want to take it all the way apart...
I can clearly see the aftermarket ignition module. Does anyone in readerland know what exactly that geeen wire is used for? MSD says it’s a “traction control “ feature but gives no explanation of what exactly it does or how to use it.
I had to do some research on that module. The MSD part I had on my car had a little dial that was used to set the rev limit, these new modules are set with a tach. Pretty slick setup.
Do you think it could be giving a pulsed output to drive some other box? It definitely “will” drive a tach accurately. I did change over to using the tach connection in the cap, but for two years the green wire from the base did drive my tach. The aftermarket tach did fail btw and I replaced it
