Club 80-90 Forums

Not sure wether my alternator has packed up .. I fitted a new water pump to my 1.9 td a week or so ago so had to remove the alternator for access. Since then the dash charge light dosent come on at all. Battery drained after a while so charged it and checked voltage which is about 12.5 running or not, so no output from alt as the connection battery to alt is ok. Was fine before removal, any ideas ?, thx

Sounds like you may have forgotten to reattach the thin 'exciter' wire. That would explain why the charge light doesn't come on (no path to earth) and why the alternator doesn't generate a charging voltage. Look for a thinner wire close to the main alternator connection.

Thanks yes there is a thin blue wire connected close to the main terminal but I left that connected so will check if there's a break near the terminal later

Are you sure you have connected all the wires to the correct terminals, there should be 3 on a diesel, battery is red and goes to b+, exciter wire is blue and connects to d+ and the revcounter signal is green and connects to w. I’d double check these first and if they are all in the right place then check the alternator has a good earth to the block, I sometimes run a fly lead to be sure.

Turned out to be the exciter wire was broken just before the terminal, must've pulled it removing alternator. May need to clean up connections as voltage when running is about 14.5ish at the alternator but about 14 at the battery dropping with lights etc on. Also the alternator terminal nut gets very hot after running for 5or10 minutes. Cheers for the advice

I was losing 0.5v in that short length also - replaced the alternator to battery cable and got the 0.5v back. Looked at the crimps on the old terminals and they were full of corrosion which is why I advocate soldering terminals that are exposed like these ones.
( People will jump on this and say that crimps don't corrode internally and are the best method but when you see it you can see that the original factory crimps do fail here)

Seconded. Crimped connections are great but the solder helps protect the copper from the elements, which these cables are subjected to constantly.

How about this factory crimped connection!

"The fire that engulfed Grenfell Tower probably started due to overheated wiring in a fridge-freezer, according to one expert.

John Glover told the inquiry into the blaze that a connector in a Hotpoint FF175BP in flat 16 of the block had a "poor crimp connection".

That meant the wires were not gripped as tightly as they should be and the connector overheated, he said."

A report by Mr Glover - a principal engineer at investigations firm Failure Electrical - said he studied CT scans of the connector and found spaces "indicating the crimp was not nice and tight".

He added: "A probable cause of the fire is a poor crimp connection.

"The overheating connector in my opinion was the first event that started burning the insulation on the wires that led to a short circuit.

"The overheating of the crimp starts the fire. It overheats, it glows, it ignites."