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I bought my 68 442 from a guy who put a lot of racer modifications on the car. I have a high Torque starter that has a solenoid but then he mounted a second one up on top of the wheel well. Anyone have an idea what the intention is for 2 starter solenoids?
I bought my 68 442 from a guy who put a lot of racer modifications on the car. I have a high Torque starter that has a solenoid but then he mounted a second one up on top of the wheel well. Anyone have an idea what the intention is for 2 starter solenoids?
Probably to power the coil with 12V while the starter is turning
I bought my 68 442 from a guy who put a lot of racer modifications on the car. I have a high Torque starter that has a solenoid but then he mounted a second one up on top of the wheel well. Anyone have an idea what the intention is for 2 starter solenoids?
As Eric said above, this ensures full voltage and current to the starter to overcome heat soak.
Typically the starter mounted solenoid has the large gauge battery stud and the S terminal shorted together. The fender mounted relay is used as the switch to turn on / off power to the starter through the large gauge battery cable.
Thanks everybody. People are telling me that it’s a Ford thing to have that solenoid up on the wheel well. So do I not need that or is it an extra benefit? Is that a thing when you’re using a high torque starter? (it’s a power master XS Torque.
—Billy
Thanks everybody. People are telling me that it’s a Ford thing to have that solenoid up on the wheel well. So do I not need that or is it an extra benefit? Is that a thing when you’re using a high torque starter? (it’s a power master XS Torque.
—Billy
Without seeing the actual wiring on your car, I can only provide the following generic response. People have been battling the GM hot start problem for decades, especially with headers. The real problem is that the start circuit from the ignition switch through the NSS through the firewall connector, to the starter has the potential for a lot of voltage drop as the car gets older and the connections get dirty or worn. In addition, the contacts inside the GM solenoid on the starter get pitted, which also increases resistance and causes voltage drop. Fixing all these individual voltage drops takes time, so a lot of people use the Ford solenoid band-aid. Basically, they use the Ford solenoid as a high current relay to pump full battery voltage directly to the GM solenoid and bypass the voltage drops. Some people like this because it also cuts power on the cable to the starter as a safety feature.
If you already have a high torque starter, we don't know if the Ford solenoid was added previously to band-aid the original GM starter and just retained with the high torque starter, or if it was done for the second reason, to kill power to the cable as a safety feature.
Another reason for the other solenoid is if your using a mini starter and still run points it also provides a resistance wire bypass signal to the coil+.
Another reason for the other solenoid is if your using a mini starter and still run points it also provides a resistance wire bypass signal to the coil+.
True, but a $0.50 diode does the same thing if that was the only reason.
Simply run a diode from the starter motor terminal to the coil. Current only bypasses the resistor wire when the key is in the START position, and the diode prevents current from holding the GM solenoid engaged after start. You can pay $20 for the diode kit like this or use a $0.50 diode and your own wire and crimp terminal.
No, having the benefit of providing a resistance bypass signal would be in addition to trying to cure the heat soak issue, The mini starter has no provision for that signal but the solenoid has an I terminal output.
No, having the benefit of providing a resistance bypass signal would be in addition to trying to cure the heat soak issue, The mini starter has no provision for that signal but the solenoid has an I terminal output.
And again, my point is that the mini starter without the "R" terminal works just fine if you use the diode. Besides, the whole point of the mini starter is to fix the heat soak problem of the GM starter. Adding unnecessary components only increased the number of potential failure modes.
The diode will fail before the solenoid will, don't ask me how I know. I use a Ford solenoid in my current and many previous applications with a mini starter mounted on the firewall and run the battery cable down the back of the engine keeping the wires away from the headers. Its been working that way for 9 years now. There is no right or wrong either way.
Kinda off the subject of this thread, but if you have a trunk mounted battery, the Ford solenoid should be considered mandatory. The idea of a massive battery cable powered at all times running from one end of the car to the other should make anyone think “what if?” It’s such a simple addition, not to mention makes the wiring for a battery cutoff a little easier.
Last edited by matt69olds; Nov 12, 2020 at 06:45 AM.
