Thread: Tdi elec problem - rev counter dead

Do you have the field connection working and the correct way around?

The field is connected to the warning lamp and is required to excite the diodes to start the alternator charging.

The alternator will usually eventually self excite but at high revs. If you don't have the tacho working and the unit is only charging at high revs, you may have the wires for the tacho feed and the "field" back to front.

Diana

Is the serpentine belt the correct size?

I recently upgraded my alternator to a 100amp model. During the process i discovered that the previous owner had fitted an incorrect alternator from a pre 95 Disco, which had a slightly larger pulley. The old belt looked like it fitted ok, but was actually slipping. Worth a look.

Geoff

The problem is intermittant - and appears on one trip in 3 or 4.

Usually it is evident from startup. It occurred with the original alternator and the new replacement - no difference.

Thanks for the replies, all food for thought.

Adrian

I also have a problem with my D1 Tdi tacho - it seems to work intermittently - or rather be binary. At idle it shows nothing, at WOT/governor it seems to show about the right number.

You may check continuity between cable and cable terminal (where it's crimped).
By pressing the crimped zone the trouble should finish.
I'm not referring to the contact between Alternator "W" tongue and terminal, but you have to check it always.

Regards