The Triumph Dolomite Club - Discussion Forum

My alternator is reading 1.25v. Since the rest is in good condition I would like to repair it.

Does any body know if this is likely to be the rectifier or regulator. If not are there any tests that I can do.

When my fairly new unit packed up, after not very much use, I found this guide to rebuilding them;
http://www.oldclassiccar.co.uk/forum/ph ... php?t=4513
However, I thought better of it, largely due to lack of time, instead choosing to buy an uprated unit from a reputable company which I'd had dealings with in the past;
https://www.ebay.co.uk/itm/CLASSIC-CAR- ... m570.l1313
It was a simple straight swap for the original, which I even managed to do myself.

I used the same ebay item, great product with no problems

Tony.

Not sure how to check the difference between a rectifier and a regulator failure, but usually when I take an alternator off and remove the rear case it becomes physically obvious. (Blackened components, melted solder, rumbling bearings)

Are you testing it in situ? If so, make sure all connections are good and that there is a good ground path for the alternator.

Hi Alan, can you say where you are measuring the 1.25V please ? If its on the output terminals with the thick wire going to the battery, there should be 13.5V here from the battery. If its with the alternator plug disconnected there is no initial field current so I would expect low voltage.
Is the IGN light on or glowing dimly ? What do you measure across the battery with it all plugged up, and then with all the main electrics on ( lights/ HRW / heater motor etc;) at 2,500 rpm ?
Tony.