First off let me start off by saying that when you make a write up copy and paste your progress in word or something because if you accidently exit out its gone forever like what just happened to me..... CRAP!!!!
So here is the write up for a dual battery, sure power battery separator, "Big Three Upgrade", and GM CS-144 alternator in a 1997 3.4L Tacoma.
- Two optima batteries.
- Sure Power Battery Separator.
- GM CS-144 alternator.
- GM CS-144 pig tail.
- 120Amp alternator fuse.
- 4awg wire and heat shrink. (my wire is green with a yellow stripe)
- Pre made 4wg negative wires. x2
- 1 Boat style battery terminal post style and 1 regular terminal.
- Ring terminals.
- Electrical tape and wire loom.
- Wire strippers and box cutter.
- Welder and angle iron.
- Camping propane tank and torch tip.
- Regular hand tools.
First off I took out the battery and alternator to see where the wires were that I was going to replace.
Then I measured the area where I was going to put the second battery and found out the Cruise Control Module was in the way just a little so I took it out and then placed the battery back up there and it fit great. I ended up making a new bracket for the CCM. Once that was finished I made a bracket for the battery to sit in and used a spare boat battery strap to secure the battery to the bracket. I mounted the battery separator on the firewall away from direct heat and started to run my wires from battery B over to where battery A is going to be. I also took my aftermarket fuse block and wired it up to battery B. (waterproof housing thanks to Zip-lock haha)
After that was all done I started to cut out all the electrical tape that was holding the main wire harness together so that I could run my larger wire through the factory wire loom (for the most part... big wire is hard to bend). Once all the orig wire loom was taken of I was able to separate the wires and replace what was needed. This is also the point that I wired up the GM harness to the factory harness. To do this I took the yellow wire from the factory harness and tied it into the furthest over small gauge wire on the GM harness then took the large wire in the GM harness and added a ring terminal and then placed it in the battery post on the alt. I just left the rest of the factory harness connected but taped it back and out of the way JIC I need it later.
Now for the tricky part. Since the factory wires go from alt to fuse block then fuse block to battery I had really finagle the larger wire to make it still fit. The wire that comes from the fuse block and goes to the battery came out of a pretty small horseshoe looking hole which I had to cut open a little bigger but I think it all still came out looking pretty clean.
Quick pic of factory vs. aftermarket wire size. (10gauge to 4 gauge)
Once all the wires were in I started working on the alternator install. Now since the GM alt is much bigger than the Toyota alt...
I had to loosen the bottom bracket that holds the alt tensioner so that it would fit the GM alt. The Gm top mount is also 1/4" smaller than Toyota so I had to fill the gap with a few washers. Make sure that you put the washers on the backside and not the front other the belt will sit crooked but once it was in I was able to tighten the bottom bracket and then work on wiring it up.
I have since moved the belt in to be on the center of the pulley that way the belt is straight. (Toyota alt has 4 slot pulley and GM has 6)
I also found it easier to take the driver tire off and to the wiring and tensioning through the wheel well since the GM alt is bigger it is hard to do a reach around on the GM alt lol.
Here are a few pics of it all put back together...
The center green wire you see in the first pic is going down under the fuse block around all the goodies on the driver side fender and into black wire loom across the firewall to battery B (pic 2)
Alright that’s it... I think. If you have any questions feel free to pm me or post em. It was a big project but well worth it. I have not had one "wink" and the other night I left all lights on for a few hours playing some midnight football.