4 Pin Alternator Question

[evolve991]

The plug on my 89 alternator is a PLFS type but only the F post has a wire. The outside of the plug has no holes where someone may have removed the other 3. I'm putting a high output CS alt in and read about the remote sensing wire being needed for true charging. Could this plug be an adapter for a 1 wire alt that someone used on the motor? (It's a transplant) On the lone Battery post instead of 1 wire going to the POS battery terminal it also has another wire that hooks up to a junction on the fire wall.

On all the articles I find about the different alternators none say anything about a factory Voltmeter. They mention tachs,hourmeters,etc being hooked to P on the plug. F is for Field Positive or diagnostics and is optional. L is for an idiot light which I don't have,I've got the factory V gauge. S is for remote voltage sensor.

 

[K85 Octane]

This is a factory plug. I pulled the serp brackets and all accessories from an early 90s newer body style truck. Just so you know. And I rewired my truck, ended up using the exciter wire hooked up to the alt. I don't know if it's right LOL, but it works. I too would be interested in knowing what I need to use in order to use the larger CS144 alternator. I already have an adapter bracket for the larger body.

 

[evolve991]

Yep thats exactly what I've got. Mine's an 89 serpentine setup in an 85 'burban. So is that lone wire in the plug your exciter? I guess the remote voltage sensor wire isn't a big deal since it's been charging OK all this time.

 

[K85 Octane]

I honestly don't know LOL

I just had the stock stuff all hooked up with my new wiring harness. When I changed over to the serp stuff, I figure what the hell, maybe it's an excite wire hahaha. Hasn't caught on fire and both volt gauges for both batteries are reading good.

 

[evolve991]

Good point! I "found" a 3 pin CS connector on Advance Autos site for 10 bucks,a 4 pin for 20,but since I know the F pin works I can use that and the S pin for a remote sensor. May not make a difference but I'll know I'm getting all the juice out of the alt!