Thread: Alternator going - Strange codes in engine module

Quote: Originally Posted by Dana @ Ross-Tech Do you have a VCDS scan to post? Have you checked the Fuse panel at the battery for melting? (assuming this is a MK4 body) I know you mentioned it, but are all of the bulbs correct in the tail light holders / sockets? As MOGolf mentioned, bad grounds can cause serious problems. I would also check the main ground at the transmission. I replaced the fuse panel and all of the fuses with the correct...

Quote: Originally Posted by NB_TDi Automatic TDIs have the 90A alternator. Sticks have the 120A. I've seen a mixture on the ALH engines. No consistency. You might think the sticks need the 120A due to the additional heat GPs, but I've seen some with the 90A. And I've seen 120A on automatics, but my Golf has a 90A. I've monitored cars with both. Some modified with high output aftermarket sound systems. It didn't...

Quote: Originally Posted by HoneyBeetle This is VERY interesting. My father told me to check my alternator, I could have a bad diode and it may be partially working. Anyhow, is it easy to test your own alternator? I would like to try? Another thing...I was told, by MRChill that a funny noise in the radio might be a ground wire issue. I don't know, but I'd like to know. A reputable auto electric shop could probably check your...

I had my alternator for my MkIV rebuilt while I watched for $170. Took about an hour. New bearings, brush module / diode pack, and clutch pulley. It's probalby time if your car has around 150K miles on it.

Quote: Originally Posted by Occams_Razor I thought the 120 amp was standard on TDI's too but I have owned this car from the factory. This is the first time the Alternator has been swapped and it definitely was a 90 amp Bosch unit. I checked ETKA and it shows that 1.9 ALH TDI's could have 90 amp alternators, (even with air conditioning). I got the stupid MIL light last night again and went in to measuring block 6 and found that...

Wow, That's odd.

It strikes me as unlikely, but it would be a logical fallacy to rule it out. -Uwe-

Quote: Originally Posted by Ol'Rattler Another way to state what Uwe said would be in troubleshooting, fix things you know are not working right so that you can rule those problems out before driving on with other problems. In regards to alternators, they are actually AC generators that have 6 diodes that change AC to DC. If any of the diodes internally short, AC will be supplied to your electrical system which could cause some of the...

I just replaced my alternator last weekend , the best buy was NAPA just under 200 USD for a 2003. Mine was making the battery light come on a just over 2650rpm not under and only when hot. My tool for checking the battery and alternator read that everything was good,with load test and all. The light would not come on when the AC was on or I had alot of power needs. After replacing it everything is good no battery at and RPM. Just another odd...

I bet if you put a multimeter set to Volts AC between battery posts on this car and another without problems you would see higher numbers on this one. Also, I haven't taken one apart but my guess is that the brake switch is not a simple set of contacts, I bet there's an integrated circuit in there that is most likely susceptible to poor voltage. Thus based on the info provided I would swap that alternator with a known good one....