hey which wires have to crossed over to what on the s5 alternator connector to do this swap? As yoou know the plug changed from the ones on our alternator's in 89 but stayed the same in 86-88.

 

It's not difficult: the plug has two leads. You cut both plugs (old one and S5 one) off, leaving enough wire.
You just try: connect them temporalily, and put the ignition switch on. If the alternator warning light is on, together with all other warning lights, you're good to. If not, change the wires, and try again.
If it works this time, you make a permanent connection.
That's the way I did it installing a Mk 3 (84-85 and S4) alternator to my 82 harness (which are different aswell).
It works.

 

Theres an alt diagram on here somewhere if you search.

But the thicker of the 2 wires is the 12v ign wire the thinner one is the one that goes to the white/blk on your cars harness.

 

Sigh....you'll have to go through the whole thing to get what you need if s5 means the 89 - 92 alternators....original pics were lost, so they had to be reposted on the second page, but the diagram itself, on the first page, somehow survived...

What's left of the Ultimate Alternator Swap Thread....

 

I did it in my 84 with a 91 alternator.

You have to cut apart your plastic plug in wiring connector after your remove the old alternator.

One altenator has leads that are parallel like | | and the other is | --.

Once you cut the plastic connector off, you just have 2 wires, with metal connectors that slide onto the terminals. Your positive wire is towards the passenger side. I believe it was either red or brown.

 

Yeah I dont even have my origional engine harness anymore, just the connectors lying on the passenger side floor. I'm just trying to figure out what color wire on the S5 connects to what color wire on the FB.

So from what I can tell from that swap thread, B/W wire on our harness connects to the W/L wire on the s5 plug, and the W/B on our harness wire connects to the W/B wire on the S5 plug.

Am I correct?

 

Yes...that's how I did it and never had any problems, even with the stock fusible box under the hood. I did buy all brand new fusible links, though.

 

I allready have a second gen fuse box in the enigne bay so thats one less thing to worry about.