No alternator at first idle - why...

Alternator brushes are shot. Easy replacement, look for a bolt on the back of the alternator.

RGds

Alternator needs to be "excited" before it will begin to charge, raising the revs does just that.

Very common, especially with Motorola alternators. It's harmless unless you start the car and let it idle for a long time with the warning light on.

Replacing the brushes was false economy for me. The whole alternator failed two weeks later. D'oh!

I've got a pair of '87 Scirocco's here. One of them does the warning light thing. Did it on the original alternator, does it on the replacement one. The other one doesn't do this at all. However, tach comes up as soon as the engine is running, even if the alt warning is on.

- Bill

the tach is run on a speedo cable similar to or the same as what your speedometer runs on so when and the same with my car a 92 passat is sticks for about 5 minutes or untill running temp 50 or 70c yours sounds worse but i am sure that mine will be soon as bad but that is really a very minor issue compared to other things but there is a solution if it is bugging u enough go in and replace the cable BUT i WARN u know as far as i understand that can be a big job do to where volks placed it in the very back and might involve taking things off to get 2 it so wait untill it die's altogether or when planing major work on engine otherwise u will pay dearly for a simple wire

My 88 Fox (gas powered) does same thing with alternator light at first idle (no tach). Small bump of accelerator pedal kills the light. Been that way since I bought it in '92. Just bought my 3rd battery since that time, so its just a cosmetic thing unless you let it idle that way. The only way I see that being a problem is if somone parks or stores his/her similar vehicle, and goes out to start the vehicle to keep the battery charged without ever touching the accelerator pedal.

I think on diesels the tach runs off the alternator - no spark signal, so they pick up the pulse there.

I vote B.

You can renew/reconfigure/repire enough to make it go away but it's much easier to just 'blip' the throttle and get the Alt feild to 'latch', (producing more out than drawing off the battery).

TBerk

You may have just explained a mystery I've wondered about for years. Without a coil, how do you hook up a tach? Thanks.

- Bill

My son did this for me some years ago. I'd gotten so used to blipping the gas after starting it, that I didn't think to tell him to do it when he went out and started my car to warm up one cold night. He started it, turned on the heat and the fan, the defogger, and the lights. As it happened, he did this for me because I was fixing something for him. The repair job took much longer than expected, and we both forgot the car was out there idling. Until it stopped and we noticed the sound had gone away. The battery was quite dead. After we jumped it, I noticed that he got out with the ALT light still on.

- Bill

I was wondering how/why a diesel even has a tach...never heard of a VW A2 diesel that had one.

I test drove several turbo diesels about ten years ago and they all had tachs. Weren't the Golf diesel's of the '90's A2's?

- Bill

Only from '90 to '92. '93 to early '99 were A3s.

Thanks. I'm pretty sure the test drives I did were in the mid '90's.

- Bill