Tim,
First I need to ask if you have made all the tests on the "bad" alternator?
Checklist:
What are the symptoms? Is it the idiot light? Is it a dead battery?
Check belt tension
Take out and take to local parts store to test.
How is your battery? How old is the battery?
If the alternator is bad when tested out of the car, take out the volgtage regulator. If the brushes are 1/4 inch long or LESS, it may just be the VR. VR can be gotten for $25 to $35.
Have you cleaned ALL the battery connections and ALL grounds. The neg cable end is above the bell housing.
OK, you have done all this.
I bought a 115 amp rebuilt alt on EBay. Normal is 90 amp. I wanted a slightly bigger alt due to the age of the copper wires-more resistance and age of electical stuff like fuel pump drawing more current. $99 plus ship.
Rebuild it yourself? Only is the VR will fix it. Otherwise it could be a weak/bad diode and you are wasting your time. Look at a Bosch VW alt rebuild info:
http://www.3dzubehor.com/Rover/Boschrepair.html
I see you are in Vancouver. Shipping/duty could be expensive.
GL
John_AZ
1988 924S + 1987 924S