I wasn't looking for you to tell me that it's OK to do something improper. I was looking for the pros and cons and opinions of what I was contemplating doing. Maybe even some motivation to just fix it right. I just hadn't intended on being insulted in the process.
Master cutoff switch
- Thread starter racecar77
- Start date
http://www.painlessperformance.com/webcatalog/largeview.php?SearchField=50105
This works great for me. They make a kit for low amp alt. on race cars (35amp) as well. This one is for high amp alt. (solenoid is rated at 250amps continuous duty).The only thing I did not care for was the fact that with the car shut off, and the master disconnect switch on, the alt. shutdown solenoid is still energized draining the battery. I fixed this problem by running a wire from a keyed ign. source on the fuse block to a 30 amp relay which cuts the power to the solenoid after the key is turned off. That way I don't have to shut off my master disconnect every time I shut off the car.
Of course, this is designed to work with a master disconnect wired in the positive battery cable. I highly recommend you wire yours this way as the others have already said. There is more reason to the master disconnect switch than just killing the engine. Most all race car sanctioning bodies mandate this rule for a reason.
This works great for me. They make a kit for low amp alt. on race cars (35amp) as well. This one is for high amp alt. (solenoid is rated at 250amps continuous duty).The only thing I did not care for was the fact that with the car shut off, and the master disconnect switch on, the alt. shutdown solenoid is still energized draining the battery. I fixed this problem by running a wire from a keyed ign. source on the fuse block to a 30 amp relay which cuts the power to the solenoid after the key is turned off. That way I don't have to shut off my master disconnect every time I shut off the car.
Of course, this is designed to work with a master disconnect wired in the positive battery cable. I highly recommend you wire yours this way as the others have already said. There is more reason to the master disconnect switch than just killing the engine. Most all race car sanctioning bodies mandate this rule for a reason.
Thanks 355_79Bu. I'm going to rewire the cutoff switch the proper way. I didn't consider that the alternator would keep the car running and didn't have a rule book handy when I wired the car. I understand the reasons for the cutoff switch. I just thought it would work correctly the way I did it. I now know different. I'll just have to fab some new battery cables and run the alt. wire to the back. Thanks for your help, I appreciate it, Lee
racecar77 said:
You only have to make one short cable to connect the battery + to the switch, and connect the ground to the battery, add the alternator wire to the batt + side and you are done.
There is some sort of cable from the rear to the front already, correct? It would connect to the switch.
8 ga. on the alternator wire.
I have a stud welded to the frame at the rear for the batt - cable, and two studs at the frame in front for the engine block ground cable, and one for all the other grounds.
Yes and no Goob. The pos. cable runs from the batt. in trunk to Ford solenoid up front. It would be way short of reaching the disconnect switch on the back of the car. Which means I have to make a whole new pos. cable or splice the existing one, which I am skeptical of doing. Neither choice is enticing, but it needs to be done. The existing neg. cables are no problem, one from the batt. to the switch and the other from the switch to the frame. I can make those work with the new configuration. I also have the stud welded for the ground and also a ground strap from the body to the frame and a ground from the engine to the frame. I am well grounded. 
After thinking about it, you're right, I can piggyback the existing pos. cable and the new short pos. cable going to the switch, eliminating the need to make a new cable or splice. I have a threaded stud on the battery terminal that will accept an eyelet terminal on the new short pos. cable.
Battery not going dead when switch left on? Or you always shut the switch off when not in use? What gauge wire is the one from the Alt to the switch? No issues?
Thanks
Thanks
There's nothing to cause a drain on the battery with it left on, its basically just a toggle switch on the + line. I shut it off all the time anyways. I've got 4 gauge going from the alternator stud to the + battery terminal.
Similar threads
