torsdag 25 augusti 2011

Alternator installation

The TDI alternator is Bosch 120 A and is way better than the old one. The connectors that exist are B+, D+ and DF. DF is connected to the regulator on old alternators, but on these newer thingys they are a signal for the engine ECU. The only sockets that must be connected are B+ (of course) and D+ (goes to the charge warning light).
But hang on - the tachometer W connector is missing! Yes, because TDI'ed cars gets the tacho signal from a sensor at the third diesel injector.
This is easily solved though. At the back panel of the alternator there are six connections spread around the edge, each connection is a clamp with two copper wires (you can see it through the vent hole on one of the pictures). That is a W tap!
I removed the plastic cover, cleaned one of the points and soldered a cable right on to it. The tachometer is moving as expected again.

A big thanks to Adam at Frej Bildelar who sorted the wiring out for me. He's the king of car electrics!

2 kommentarer:

  1. Hi, great site and source of info.

    I've used your tip/ide on my vanagon. I was however wondering if know how accurate the thaco is after the mod? Have you calibrated the thaco in any way?
    Best regards from Norway

    Here are a link to my car on youtube if you are interested.

    https://www.youtube.com/watch?v=1oCYONeR7_o

    SvaraRadera
    Svar
    1. Good that someone can use the info. :)

      On the backside of the tachometer there should be an adjustment screw. I haven't put any energy in fixing the RPM on the tacho, I've done new back panels for both the tacho and speed instead.

      Radera