charging problem

[thetalon92]

hey everyone!. just looking for a little help. I just got finished swapping in a 6 bolt from a 91 into my 92 tsi, and came across a problem when i was driving home. The car started fine at the shop idled normal, running fine,air/ fuel good, timing good but, half way home, i slowed down for a stop sign, the lights dimmed and it stared idling like it was cammed really rank, dipping down to 700 and revving up to 1300 or so. But i managed to get it home and parked fine but after i shut it off it would need a boost to start it. i replaced the battery and it still has the problem i also tested the alternator (with a volt/ohm meter) and it was charging fine? im a little confused right now so if anyone has had this happen snd figured it out, please let me know. i hope to hear back from someone soon. Thanks. and hopefully i can be running good again. alsoany tips on what to check would also help out

 

[DSM1G90]

Are the connections from wire to battery clean and super tight without any corrosion?

Also, see if the battery wire that attaches to the ALT (being the single wire that attaches to the back of the alternator) is super tight.

(how many KM is on your ride and is this the original ALT? - if so, a 19yr ol ALT is super tired..)

If these all match up okey then:

ALT is going out (usually the brushes have worn down inside).

Plan on a replacement, or rebuild real soon.

They don't last forever.

Good luck-DSM