External Shut Off

[Gospel Runner]

I wired a shut off switch outside my trunk near the battery I put inside the trunk. I have a zero gauge wire going from the switch to the frame. Another zero gauge wire going from the positive battery terminal to the starter. I was told that I need a wire from the negative side of the switch to the field on the alternator to make this work. I have two field wires on my alternator. Which field wire do I use, and what size wire will work best? Let know the best way to proceed? Thank you!

 

[Lefty71]

What switch are you using?? Not sure I understand your wiring explanation. We don't switch the negative side like the old days. Some people have had issues with alternator providing power even tho the switch is on the kill setting, but not all.

 

[rbkt65]

if you have a on/off switch like a race car, follow the instruction per nhra rules. wired wrong ,as stated above, will not kill the car as required by nhra if such a switch is used.

 

[multimopes]

wired wrong ,as stated above, will not kill the car as required

Mine was done that way by previous owner. It still is,(I don't race it). I did however, test my alternator by switching it off, Lol!

 

[dvw]

Assuming you have a two post switch. And you are using the factory double plug alternator with the flat voltage regulator with the triangle shaped plug. The wire to the frame comes from the negative post of the battery itself. Your positive zero gauge wire goes from one post of the switch to the front of the car to feed power to the starter, dash, etc. The other side of the switch goes to the positive battery post. Now for the alternator. Disconnect the blue field wire at the alternator. You will not use it. Run a new field wire from this alternator terminal to the switch post that is connected to the battery. This will require you to make sure the switch is in the off position when the car is not in use.
Doug

 

[Gospel Runner]

Thanks Doug, I will try that tomorrow and let you know how things work out!

 

[33 IMP]

I am using a two pole switch with an actuator rod to the outside of the trunk, and i wanted to keep it. Problem was, the alternator (100 Amp one wire GM) would keep the engine running.
I bought the moroso alternator shut-off relay, problem solved, but man that sucker is expensive! $108 at summit. I sure don't remember spending that much for it. The flaming river with four poles that shuts off the battery and the alternator is under a hundred. Too bad the flaming River switch wouldn't work where I wanted it.

 

[Gospel Runner]

It did not work.
I have the positive side of the battery going directly to the starter with a 0 gauge wire. The negative side of the battery is going to the shut off switch then to the frame in the rear, and directly to the block; both with 0 gauge wires. I have a 10 gauge wire going from the shut off switch to the alternator. What am I doing wrong?

 

[dvw]

Do you have a cable from the starter feeding the Large stud on the starter relay? Here's what it should look like.
Doug

 

[Gospel Runner]

That is a good diagram. I am going out to the garage to make it happen! I will report back in a little while! Thank you!

 

[Gospel Runner]

I wired everything according to your diagram and it still did not shut the car off. I even tried to exchange the two field wire positions, and it still did not work.

 

[Gospel Runner]

A few years ago when I was just getting back into this car, it had an old wiring harness with wires going everywhere, clipped and reconnected and all different colors. In order to make sure the alternator was charging my battery, I put in a single wire directly from the starter to the alternator. Now that I have a new wiring harness, I still have that wire connected. Could that wire be the problem, since the new wiring harness has a wire connecting the alternator in the system? Should I disconnect that old single wire and retry the newly wired switch?

 

[dvw]

Sorry my mistake. I was thinking 4 pole switch. Using a 2 pole switch there are two ways to go about it. # 1; run the alternator output wire all the way to the battery side of the switch. I would suggest 6 gauge wire. #2; install a relay in the field circuit. Any generic relay will work. See attached pics. The relay wires are at the pin numbers illustrated. all relays will have pin numbers 30,85,86,87.
Doug

 

[Gospel Runner]

For #1 to work, I should disconnect the starter to alternator charging wire, and run that line to the switch? I need to go to Lowes and get some more wire.

 

[Gospel Runner]

Hoorahhhh! Doug if I ever run into you, lunch or dinner is on me! At first, I was disappointed when it did not work. Then I disconnected the the charging wire from the harness to the alternator, so there was only the wire from the switch on that charging post. It worked. I just taped off the end of that harness wire. What a huge relief!!! I just have one more dumb question. Is my alternator still charging the battery with this set up? Thanks to each of you for helping me. I know you could have said, this guy is dumber than a rock, I am done with him! You stayed right there with me, until it was figured out!!! Thank you!!!

 

[dvw]

For #1 to work, I should disconnect the starter to alternator charging wire, and run that line to the switch? I need to go to Lowes and get some more wire.

Yes if you look that wire has been eliminated in the #1 diagram in the last post.

Then I disconnected the the charging wire from the harness to the alternator, so there was only the wire from the switch on that charging post. It worked. I just taped off the end of that harness wire. What a huge relief!!! I just have one more dumb question. Is my alternator still charging the battery with this set up? Thanks to each of you for helping me. I know you could have said, this guy is dumber than a rock, I am done with him! You stayed right there with me, until it was figured out!!! Thank you!!!

No it will not charge this way. l make dumb mistakes as well. There are no dumb questions. If you want to succeed you must learn. I still learn everyday. So if I can help someone figure something out thats good. What comes around goes around.
Doug