General Wiring Advice for my swap

[Baja Blazer 85]

Hello,

I'm swapping an L32 V6 (out of a 1994 Camaro) into a 1985 S10 Blazer.

I plan to run the 1994 Camaro PCM harness as a stand alone separate from the Blazer's chassis harness. At this time, I've figured everything out from VATS to VSS (in theory of course, but I'm confident).

HOWEVER, one thing I'm having trouble wrapping my head around is how to wire the alternator and the battery terminals. I will have two separate harnesses (chassis and PCM). Unlike the fuse blocks, which I can have one block for each harness, I can't run two batteries and two alternators respectively for each harness.

I know in my gut that this is a simple issue, since standalone PCM harnesses aren't unheard of. But what's the actual solution for it?

Input is greatly appreciated!

[Guest]

You can simply combine the battery charge wires, it's just simple power.

When your strip everything out of the F-body harness that's not needed you'll be removing the alternator wiring from it anyway so you use the S10 alternator wiring for the alternator.

Why not just use the TBI system off the S10 on the 3.4?

[Baja Blazer 85]

You can simply combine the battery charge wires, it's just simple power.

When your strip everything out of the F-body harness that's not needed you'll be removing the alternator wiring from it anyway so you use the S10 alternator wiring for the alternator.

That explanation of battery wiring makes sense.

Using the S10 alternator wiring on the Camaro alternator seems very incorrect to me. You're going to have to expand on that.

Why not just use the TBI system off the S10 on the 3.4?

The S10 didn't use TBI (remember, its 1985). It was a computer controlled Rochester carburator. Which is the fuel injection equivalent of a drunk man spraying his liquor over the bar and lighting it with a match. All that aside, I still have to abide by California Emissions Standards.

[45es]

That explanation of battery wiring makes sense.

Using the S10 alternator wiring on the Camaro alternator seems very incorrect to me. You're going to have to expand on that.

Compare the wiring diagrams of the S10 and a 1989 Camaro. I believe you will see the alternator wiring is the same although you will need the connector that plugs into the '89 alternator (get at flaps). The modified wiring harness with the new plug will allow you to use the '94 alternator.

[Baja Blazer 85]

Compare the wiring diagrams of the S10 and a 1989 Camaro. I believe you will see the alternator wiring is the same although you will need the connector that plugs into the '89 alternator (get at flaps). The modified wiring harness with the new plug will allow you to use the '94 alternator.

So you're saying I will need to get the 1989 Camaro alternator pigtail: https://www.google.com/search?q=1989...w=1366&bih=677. And this pigtail will work with the 1985 S10 harness, but will also will plug into the 1994 Camaro alternator.

[45es]

Essentially yes. The plug will fit the '94 alternator. What this plug/wiring does for you is allow for the alternator voltage sensing wire to come from a location out in the electrical system. This provides better regulation of the alternator output as apposed to how the '94 system is wired. The plug used with the '94 system creates a situation where the voltage output is sensed right at the alternator output. Although this would work for you, the alternator never sees the true load placed on it.

[Xnke]

Basically, your stock 94 Camaro alternator is a "one-wire" regulator, but by simply changing the plug you can convert it to conventional "three-wire" operation and get much better voltage regulation.

I am doing the same swap into my '91 S10, L32 V6 with the 1995 PCM. The alternator wiring is some of the easiest in the entire swap. The most interesting part is the power supply to the PCM, and the interfacing for the electric fuel pump relay. (how many circuits did you need, GM??)