Would this work?

[Steven 10+ year member]

I am looking at mounting two alternators in my 1985 firebird. It has a 2.8L V6 MPFI.

what I want is basically a second electrical system in my car for just the stereo. That way if I run the stereo without the car being started it cannot kill the battery that I use to start the engine. I would also like, if possible, to use a Ford selenoid to momentarily connect the two circuits so that if I say, leave my lights on, I hit a switch in the car and "boost" myself off my stereos battery.

I am having a special bracket built to hold it. The part I'm concerned with is wiring. Frommy understanding you have to keep the two alts on separate circuits. Now the posative side isn't going to be too hard, just wire everything onto the second alternator output. But what about the ground. The alternators ground is the vehicle chassis, How do i separate the grounds from eachother, or do I have to.

For the boost capabilty I was looking at using a ford selenoid. I would wire the positive terminal on one battery to one side of it, the other side would go to the positive terminal on the other battery. A switch in the car would be connected to the "start" terminal on the selenoid. to my understanding this create a "bridge" between the two electrical systems, allow me to start my car off the second battery. I then turn off the switch and isolate the two circuits again.

Will this work? Any foreseeable problems?

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[Jasontb2000 10+ year member]

Simple. Just get one of those Batt. Buddies. If you car won't start then just turn the switch to let the reserve and starter up!

 

[rco8786 10+ year member]

You might have to just ground everything straight to the battery...that's the only way i see it being done. I would say buy like 2-3 00awg wires and bring them all to one point and mount them somehow and ground all your audio stuff to that.

 

[Alaxan 5,000+ posts]

I would not mount all of the audio stuff to the same ground, but the two alternators grounds should be fine at same location.

 

[Steven 10+ year member]

Hey people. i got the second Alternator installed and it works great.

One last question: If I was to temporarily disconnect the feild wire will it damage the Alternator?

 

[Jasontb2000 10+ year member]

Alright!! Like I say, you have to have the power to make the power. Now try placing 4 alternators under you hood with 16 Memphis HPO-154D 12" subs and 8 16-st1500d memphis amps in the! Not to mention Mid's & High amps, x-overs' etc. Very tight fit. I will contact the Mech. shop that did my alt. work and find out the answer for you!