My friend and I are putting a motor in his 1989 Camaro. It originally had the 2.8L V6, serpentine belt setup. The alternator(original) had 4 wires connected to it in a single plug. The alternator he is using is the 3 wire type; 2 wires in a spade-looking plug, and 1 heavy wire that bolts onto the back(+12V). What wires should we use?

I'm searching my books now, but I don't have any for his year.

Gotta get this 383 online so he can make a 1320 footer this Saturday...

 

If you use the 3 wire, here's how to wire it:

single heavy wire from the back goes to the battery*

one wire from the spade plug goes to the 12v+ wire to the alternator*

one wire from the spade goes to alt. gauge

*these wires are usually connected to the B terminal of the starter, which in turn is connected to the battery positive terminal. yup, all 3 wires on the starter.

 

On 3 wire CS series alternators as was said heavy wire in rear goes through a fusible link to the battery, the Red wire in the 2 pin plug goes to a Ign HOT source and the thinner tan colored wire is the sense lead. On 89 models it ties into the fuse panel at the blower motor fuse to sense large voltage drops and throttle up alt output. If you want a schematic of the various wiring schemes for the CS go to www.alternatorparts.com. They offer an online service manual with wiring instructions.