I relocated my battery in the trunk, but, in order to drag the car, I have to have a battery disconnect switch located on the back of the car which will kill the car when you disconnect the positive battery cable. This cannot work with stock 3-wire alternator, as the power for the alternator goes directly to the starter solenoid. When the car is running, you can totally disconnect the battery from the car, it will stay running, I know because I tried it.
With a 1-wire alternator, it will work because the alternator connects directly to the battery, not the starter solenoid. With the mustang, if I disconnect the power wire from the alternator to the solenoid, I can then start the car and run it off the battery, and then disconnect the battery to kill the car. Obviously, I cannot run the car like this as the battery would not be able to run the car very long without being recharged. I don't know if I can run the wire from the alternator all the way back and connect it directly to the battery or not, plus, I don't want to do this.
Does anybody know of any other solutions, or what other people are doing?
If your talking about with the stock setup, it doesn't, I tried. The alternator is supplying all the power to the motor once its started, I totally disconnected the battery from the car, I could have taken it out of the trunk, and the car still runs and drives fine.
"Even with your master disconnect turned off, your engine may continue to run due to alternator feed back. This relay is installed between the alternator and the battery. When the master disconnect is switched off, the relay is de-energized and stops current flow to the ignition system. Includes all hardware and installation instructions.
If the above link doesn't work - go to http://www.jegs.com and look at part # 764-50103. It's made by Painless Wiring and runs $37.99.
Just a question though, will this work for a non 1-wire alternator such as a stock ford mustang one. I can see how this would work for a 1-wire alternator which connects directly to the battery, but with the stock ford alternator, it does not hook up to the battery, it hooks up to the starter solenoid. Would this device then be installed between the alternator and the starter solenoid? If you are not sure, I can call Painless Tech line if they have one and ask them.
I ran a 6 gauge wire from the switched side of my battery disconnect(the battery post side) up to the alternator wire that used to go to the solenoid and junctioned the two wires together. I think that will shut it all off. The basic situation is that you have to isolate the alternator charge wire from the rest of your electrical system or the alternator will carry enough current on the charge circuit to keep the motor running through feed back.
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