New Generator Mystery

1967 3000 BJ8... owned since 1969.. last month the generator light came on... tested generator... nothing.. gen original to car..I have replaced brushes before.. decided maybe it was time to get a rebuild and replace it.. got new gen.. installed and polarized... tested..getting 14 volts at 1000 rpm... gen light on at idle of 1000 rpm... slowly raised rpm.. light went out at 2000 rpm ..lowered rpm... light stayed out till back down to 1000..stayed consistent... original voltage regulator ... I thought 'ha'..I can solve this problem.. spare voltage regulator on shelf.. I have had it 15 years..still sealed in bag..still in the box... installed.. now gen light stays on all the time !!!!.. checked connections.. re-polarized gen.. didn't open up regulator..I see some saying to clean the points inside.. I'm a bit stumped..

Re: new generator....

It's not difficult to access the points and check them. Or you could try a new solid state regulator. Or some other issue that will take more detective work may well be the cause of the problem.

The regulators seem quite durable. Recently, I thought that the original style regulator on my 100-6 was not working right. It looked quite grungy inside, so I replaced it with a new solid state regulator. That did not solve the problem, and I had to dig deeper to solve the issue (turned out to be some other wiring issue). After installing the shiny new solid state regulator, I left it installed, even though the old one likely was still fine.

Even tho your second regulator was in the original packaging I would suspect that the points were not that clean. Just oxidation from all those years would do it. I would pass some fine (maybe 600 to 1000 grit) paper across the points to clean them up. If that doesn't do it and you are sure your wiring is installed correctly, then I would start at the beginning with the test that the book describes.

Start at beginning, is belt tight enough and correct size? Prob cheapest point to start with.

Hi All,

Randy has a good point.

When changing from generator to alternator with internal regulator, all looked good but after every start-up and during a short test drive the charge light would begin to glow brighter and brighter. Upon return to the garage and after a short engine cool down, investigating all components within the engine compartment, presented no issues. Originally thinking the new alternator was the culprit, I returned the unit and installed the replacement with no satisfaction. Since both alternators were Delco rebuilds, I purchased a new unit but again experienced a red change light. Again, returning the new unit to be checked, no issues could be found by the manufacturer and again the new replacement provided also turned the light on. Since rewiring a few times and 4 alternator replacements did not seem to correct the issue, I was ready to return back to my generator.

Scheduled for a local town car show, I attended the gathering as it was nearby and felt I could easily run on the battery if needed. However, on the drive home with headlights on, again the charge light began glowing and for some reason I pulled over, stopped the engine, and opened the bonnet to briefly investigate. Moving my hand around the alternator, I happened to hit the fan and it moved easily. Problem solved. It seemed that when the belt was cool or cold, it would grip the pulleys. However, with a little engine heat the belt would begin to slip until it had no grip at all. As it cooled, the belt would again regain proper grip and the alternator would charge properly. Changing the belt resolved the issue.

Just one of my Healey experiences over the years,
Ray(64BJ8P1)

problem solved ... I opened the old voltage regulator and the points were pitted just a bit... I used 600 grit sandpaper and cleaned them.. gen light stays out even at idle !!!!..new 'old stock' voltage regulator never worked..opened it.. cleaned points.. still a mystery.. but easier to get a new one if needed...