I own a 1988 N/A Convertable. (just for reference) alright so I noticed a few days ago that when ever I turn on my heater the rpms begin to stumble, same goes for when I operate my power windows, turn my headlights on/highbeams. I checked my alternator belt and its very worn. So I know what the cause of it is. I was just wondering (just to reassure myself) if there could be anything else wrong besides the fact that the alternator belt is worn and cracking. The battery is somewhat new, and this has only started happening recently, but before, my rpms would drop when i turned on the heater and did all that other stuff i just listed but it wouldnt stumble(also wondering if rpms dropping when turning on these things is normal??). I also did the ecu grounds in september so they should be fine. Any advice or theories would be helpful. Thank you for your time. :-)

 

Is it grounded properly?You may have a bad alternator in which case you may just want to upgrade and buy a used FD one.Unfortunately I also have a alternator going out on me.

edit:also you may want to search next time, I found this answer in less than 1 minute using the search function

 

You can use an FD alt on an FC? Just curious as to what the benefits are? Very interested...

 

BAC is disfunctional.

 

The FD alternator puts out more than the FC.The FC alternator often has problems when stereos are upgraded or more mods that use electricity are added.The FD alternator puts out over 100+ amps or something around that compared to the FC and 60 or 80 amps depending on s4 or s5.

 

S4 alts put out 70 peak amps
S4 alts put out 80 peak amps