stang_kllr

iTrader: (6)

It may have been covered already, but I searched and couldn't find it. Someone please help, after switching to the MSD, how do you wire the alt. to excite it? Im tired of having to jump start everytime.

jonz

iTrader: (1)

I just used a keyed 12 volt wire and a resistor to knock it down to 5 volts I believe

stang_kllr

iTrader: (6)

sounds easy enough. so just 1 wire still correct? I read something about people using a light bulb to do the same thing. Im curious as to how much ohms I need to add in.

jonz

iTrader: (1)

Don't remember what resistor I used got them from radio shack but I've heard of people using a light. But yes I just used the stock plug with one wire and used the b terminal on the plug

Pony Exp.305

iTrader: (6)

resistor 470K I think so.

TTur1996

We have the MSD alternator also. One wire straight to the battery cable through a high amp relay to turn it off and on. That cuts it off completely to keep power from bleeding back through your wiring harness. The alternator senses voltage. If there is still a draw. Like from your ignition. The alternator will stay engaged being its a one wire alternator. The relay we have is made by Moroso Part #74107 I'm sure there are others probably cheaper. You just need a switch to turn the relay off and on. Tried the light bulb and resister deal. Not an exact science. Usually fails or has intermittent problems. Good luck. This is just what we did. Not saying it has to be done this way. Just a suggestion that works perfect with 0 problems.

stang_kllr

iTrader: (6)

awesome! thanks for the info guys.

TTur1996, do you just run a switch on the power side pin 30 or on the ground side of the relay? Also, when do you turn the switch off, and why would you want to?

TTur1996

One control wire goes to ground and the other control wire goes to a switch then to a 12volt power source.

TTur1996

When you turn your key off on a stock alternator. There is a wire going to the regulator to turn it off to prevent back feed to the system. On a one wire alternator the only wire is the charge wire. The regulator senses voltage and charges accordingly. So when you turn the key off it is still sensing a power draw from the ignition or whatever you have running, fuel pump, radio, or whatever since you have it going to the stock wiring harness. And that's why your motor will stay running. Using a relay you cut the power completely from the alternator. Not allowing it to back charge the system.

TTur1996

The single charge wire goes through the relay to your starter or your battery. The switch is to activate the relay. If your running a 16 volt battery you can shut the alternator off to pull less power from the motor and you don't have to worry about voltage drop to your ignition then turn it back on after the run. On 12 volt you would want to leave it charge so can maintain 13-14 volts.

1981TA

iTrader: (7)

So why not just use a resistor?

TTur1996

I was under the impression it was a one wire MSD alternator. Not one with a plug in. Besides that, as I already said. Its just what we did. Do whatever makes you happy. Just trying to show other options. To each is Own.

1981TA

iTrader: (7)

no worries, I think I misunderstood. I was thinking of stock GM alternators.

stang_kllr

iTrader: (6)

yea its for a stock ls1 alternator. thanks for the help guys.

zamora7

iTrader: (4)

Or you can get one from Ron Francis wiring. That's what I did, just getting done wiring everything on hopefully it works like it should.

booboo37

iTrader: (43)

I like to use a circuit breaker for safety...

zamora7

iTrader: (4)

My set up world like a charm. I can finally move on from the wiring part of the project and go on to the suspension.