zzeeexlover

So, I have an 88 and I am having charging issues. I am pretty sure there is a short somewhere in the system, yet have been unable to track it down. The issue is though, that my battery won't hold a charge, both the battery and the alternator test good though. If I run the a/c (yes I am spoiled : P ) the car runs on battery and dies. It only seems to be charging at 12, and sometimes lower than that. I thought I had the issue solved and when I did I added an electrical fan to help keep the car from overheating. I apparently didn't find the issue because it's still happening. I have checked all the wires that I can visibly see and I can't find anything. My wipers (not sure if this is even related, or if it's the cause) only work on one speed, low. I have changed out the motor once and the switch twice. I am not sure what to do anymore. So, here I guess is my main question. Can I take the alternator out of an S5 and put it in my S4? Since I know it has 10 more amps, will this at least help until I can get the money to hire someone to track down this issue?

JustJeff

iTrader: (13)

Wiper is probably unrelated. Wiper switches going bad on 2nd Gens is pretty common. I don't have low working on mine.

There is a difference between S4 and S5 alternators, well beyond S5 being rated higher. Here's a link to get you started on that topic.

https://www.rx7club.com/showthread.php?t=783859

As for the electrical issue, your electric fan is adding more draw on your system. 2nd Gen alternators are notorious for being just enough to keep the OEM electrical system up and running. I don't know enough to help beyond that.

zzeeexlover

But this was happening before I even put in the fan... So I am not sure that it's the fan causing the issue.