regulator/alternator problem?

[Marty Levenson]

Dear Don and others,

After a couple hours of motoring, I noticed the dash ammeter twitching rapidly from 0 to about + 20 several times as we idled down to dock the boat. It may have done that at other times..don't know. Later I tried cranking: it turns over fine and starts right up, but the ammeter is staying at 0.... it usually goes to +30 for a few moments after starting and slowly comes back to 0. I tested the batteries...both around 12.4V, but the reading directly off the alernator (engine running, no loads) was also 12.4V.

Am I right that I should get a higher reading from the alternator? Does this indicate it is either the regulator or the alternator at fault? (did check the belt...its tight) The regulator is completely solid state and says "Traspo - replaces VSH 6201 12 v neg." The alt is stamped "ALK 6204 A27" The boat is a day's travel away, so I'm wondering about bringing a new regulator next time...does that seem logical?

Thanks in advance,
Marty

[Don Moyer]

Marty,

I agree that your regulator could be defective, but I'm also wondering if there could be a loose connection on either side of the ammeter - or even within the ammeter itself. The ammeter is connected in series with the alternator, which means that the charging circuit depends on the ammeter to maintain continuity within the system.

I have no experience with external regulators, but I would think that you should be able to pick one up at a local automotive starter/alternator shop.

Regards,

Don

[Marty Levenson]

Dear Don,

Thank you for your reply.
I was able to buy a rebuilt OEM 35 Amp Motorola (with regulator) to take to the boat next weekend. I'll see if swapping that in fixes the problem, and if so, take the old alt + reg home to test and repair for a spare.
If swapping doesn't solve the problem I'll certainly check out the ammeter in more depth. If I understand the schematic correctly I can just jump past it if its not working (?)....and will also check the connection.

Thanks again,
Marty