Alternator, 120 or 90 Amp

When using an AHU in a Mk2 with NO AC, will a 90 Amp alternator provide enough juice?

Except for the TDI, Mk3 four-cylinders with AC use 90 A alternators. Glow plugs take quite a bit of current, but only for a brief time.

I would think with a good battery you should be ok.

Manual or automatic transmission?

Manual transmission TDIs generally have 3 additional "coolant" plugs at the head coolant outlet, to help the car warm up faster in the winter, and thus shipped with 120A alternators.

Auto transmission TDIs use a heat exchanger in the transmission to do the same thing, so no coolant plugs and thus a smaller 90A alternator.

Thanks for the info, Vince. Forgot about the three heaters in the water outlet.

10-12 amps each, if only for a few minutes... but at the same time as your glow plugs and heater fan and rear window defogger and heated seats and headlights and cold battery and...

At least that's the case up here in the frozen North.

Based on your climate, CGPs may not even be needed. I wonder how many of these strip fuses are blown, without owners knowing ...?

-Todd

My previous to me 2000 Jetta has had a 90amp Alt on it for over 100k miles.. no problems.