Thread: rev counter off and charge light coming on - alternator ?

On a Diesel (200TDI and 300TDI) the tachometer is driven off the alternator. Fluctuating then Zero RPM is an indication of a failed alternator (probably the regulator pack). I had this happen twice with my 200TDI - you may or may not get the charging light come on.

Hi Steve,

I would recommend getting the charge voltage checked, especially if your in Albany and intend on driving back. These cars run on electrons not fuel...

It certainly sounds like one or more diodes have given up and it will probably leave you stranded some where...

I had a similar experience with my Commodore, I didn't attend to the flickering Alt warning light; only to be stranded half way between work and home when I ran out of battery power to drive the engine ECU.

Cheers
Ron

if the alternator has not been over loaded, the diodes might be OK and it may be just the brushes need replacing.

FWIW: start the engine, pop the bonnet and give the alternator casing a couple of sharp taps with a wooden mallet /piece of 4x 2.. and watch to see if you get any black dust emerging from the front of the alternator...if so, sure sign of brushes on the way out... (learned that trick last July from the NRMA bloke) in which case you just might be able to get a new set from a competent auto electrical bloke in Albany...
good luck!

I think I've got some Bad News for you...

My '95 Classic's tacho died too, plus a growling noise rom the alternator when the engine hatch was opened.... Charge light stayed off, but alternator was very hot to touch.... - Internal short(s).

Cost me $545 from Rovacraft in Bassendean 13 months ago.
(I've got the box sitting on my desk)

Rovacraft's part No. is AMR3107 for 100Amp DENSO unit, manufactured in the EEC

I believe others have managed to source an equivalent from BOSCH, but dunno for sure. - $545 IS a lot of money, IMHO - Give the casing a LOT of belts/thumps/threats of GBH as Hoges suggested.... !

Problem is, the engine room on a V8 is so incredibly hot that everything is running at its limits. Alternators/regulators don't thrive on HEAT.

Intermittantly working/not sounds like a LUCAS type fault... defective solder joint perhaps, if you're lucky...

Steve, I'm in Albany and have tools if you need a hand, where are u camped?

Roger

Thanks for the suggestions.
I think I'll replace the bushes back in Perth if it makes it that far, so I'll chance my arm for the trip home on Tuesday.
So if ya see me and a caravan getting a piggy back on a yellow taxi, wave

So what did the multi meter say, is the alternator good to go or is it stuffed?

Your keeping us in suspense.

Cheers
Ron

Pull the brush holder out and see if it's just a case of brush dust retaining the brushes inside the holder. I recently had this, used compressed air to blow it out and the springs were able to push the brushes out to slide on the comuntator (spelling)