Hi guys, I have an 85' Trans-Am that I want to do a trunk mounted battery in. I have a nice battery box, 1 gauge monster cable, master disconnect switch and everything else I need.
My question to you is, whats the best route to run the cable to the solenoid, and what do I need to do to set it up so the switch kills the motor. I cant have the motor running on the alternator when the disconnect switch is off.

I can either run the cable through the car, out the firewall and tie it into the existing battery cable, to power the starter. Or mickey mouse it around the exhaust to the solenoid ????. I think it might be easier to run it out the firewall and run a power distribution block, to power everything.

I've done lotsa' trunk battery's, but I always had a full frame to run the cable through, I know, thats cheatin.

You guys rock, and ya know alot more about 3rd gens than I do !!!.
Thanks guys.

 

I am in the middle of this too, debating which route to go as well. Would like to keep it in the cab for the protection but can't find a good location to come out the firewall if run inside. (passenger side)

For the alternator cut out, I am going to install a relay that is hot(energized) when the ignition is on. If power is dropped by the cut off switch, the relay will drop out. The contacts of the relay will be in series with alternator enable wire. (LS1 alternator)

Same idea can be used for a SBC alternator, but the relay contacts will need to be sized for the output of the alternator, as there is no enable charging control. Not sure if there is a better route than this...

I am powering my interior through the C100 with the Oranges on the starter solenoid like stock and then have a Painless Block for distribution of power for the LS1 engine power needs.

My plans are to run 1/0 cable from the cut off switch to a large distribution point in the front on the passenger side. From there, #1 cable to starter solenoid and a #8 to my distribution block. (Rated for 40 Amps)

I will let you know how it goes ...

 

Hello, thanks for the input bro, I appreciate it.
I looked and looked but I couldn't find a sweet spot to drill through the firewall on the passenger side of the car. However I found the perfect spot on the drivers side.

I centered my battery box in the rear of the car and ran my 1/0 monster cable to the master switch. I am keeping the switch onside the car mounted to a metal L bracket bolted to the floor. To use the switch outside the car, I picked up a long drill bit, about 3/8" and about 16"-18" long. I drilled a hole through the top right hand side license plate bolt hole.

I ran the hole all the way through into the back of the car, it was fairly easy actually. I got a piece of allthread that will slide through the hole to the inside of the car. I am drilling a hole through the switch handle that the allthread will slide through, I am using a couple lock nuts and washers to secure it to either side of the switch. I plan on using a mr gasket shifter t-handle outside the car to activate / kill the switch. And it'll look killer. Also I can remove it quickly and easily. It only needs to be on at the track, and stops people from stealin' the handle and killin' the switch when i run around town.

As far as the firewall went There was way to much stuff in the way on the passenger side. My answer was on the drivers side. There is a nice flat spot just under the brake booster, here's how you do it. Pull the plastic panels on the drivers side of the car, the rear kick panel next to the seat, the door sill panel, front kick panel and lower dash panel cover. Run the cable under the carpet up to the dash area, and pull back the carpet and insulation. A lil' way down the firewall under the steering column, you'll find a pigtail going through the firewall.

Jog about an 1 1/2" - 2" to the left of the pigtail and there ya go. For my 1/0 cable I used a uni-bit / step bit and ran a 3/4" hole right there. I fought the grommet a lil, but i got it in place, I used the uni bit and worked the grommet around to make sure it was seated and rounded out good. I worked the 1/0 cable through it and it pop's out conveniently under the brake booster in the nice flat spot. btw, a 1/0 cable lug won't fit through the size of hole I drilled, I just used the drivers side shock tower to hammer a new one on.

My alternator answer was easy, i'll run a relay to the field wire plug. The "Field" is the alternator on / off switch. When its energized, it tells the alternator to charge. When it loses power, the alternator stops charging, killin' the motor with the switch.

I found 2 kool sites you'll want to check out. Here are the links.

http://www.gmhightechperformance.com...ech/index.html

http://www.chargerr.com/Alternators/ALT.HTM

Hope this helps ya, enjoy. I'll have pics up as soon as its done !!!.