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Old 02-10-2019, 08:09 PM   #9
FireSale
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Join Date: Feb 2014
Location: Lakewood Washington
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Default Re: Starter solenoid

i have one of those red MSD starters that probably came off a 747 based on the torque it provides. It doesn't require a Ford style relay/solenoid and has a wiring diagram that allows a 12 gauge wire to basically be connected directly to a start switch. Only problem was that this provided for the big wire on the starter to be connected directly to the battery at all times when the car was on. My steering shorted it out making a hard turn to get to the staging lanes. Burned out a 150 amp cutoff switch. I wound up wiring in a Ford solenoid to manage the battery power during start. My current headers won't clear the starter and I don't miss the drama.


On a side note, I have found that continuous duty Ford style solenoids make very good relays. They cost more but are very reliable.


Another trick: If you use a Ford style solenoid fender mounted to send power to the starter, there is a reverse voltage surge that travels on the small wire back to the starter button when the switch is released. This is caused by the collapse of the magnetic field in the solenoid and can damage the starter switch or wire to it. I replaced a push button with thin gauge wire with a beefy momentary toggle switch and 14 G wire because of this. You can also wire a diode in that small wire to block reverse current if you understand those things.
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Dale Shearon
68 Mustang 6394
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