regulator failure

 Just replaced my voltage regulator again after less than a year's
service.

This is an automotive type 3 wire regulator, energizing the alternator
rotor through slip rings.

Is this second failure pure coincidence and bad luck or could there
be a problem such as a high resistance or bad diodes taking out
the regulators ?

Any insights or suggested diagnostics appreciated.

 
Assuming your battery's okay, get your alternator checked out by someone
good. There are various things a failing alternator can do that will fry a
voltage regulator. Worse yet, the obvious symptom is a failed regulator, and
the guilty alternator usually continues to put out some power, so many will
just replace the regulator and look no further. (Had a sports car years ago
that was eating regulators. After replacing the third regulator, my mechanic
figured there had to be more, and found my alternator had a loose wire that
*sometimes* flopped over where it didn't belong, zapping the regulator.)

 
Come to think of it, I fried a regulator years ago with a bad
path to ground.

I've already cleaned up the battery terminals which had gotten
crapped up in the humid weather but I should look deeper into
the guts of the charging system.

Thanks

 

This problem has been discussed in detail for the past 10 years on the
VFR list.

http://tinyurl.com/ystg5k

Here are the Cliff's Notes on solutions.
Run a large diameter ground wire directly to your battery from the RR.
Make sure it is getting a good supply of cool air. I mounted a
computer fan to mine.
Clean the back side of the RR, the mounting area and apply dielectric
grease to the mating surfaces.
Clean all connections. And if you are really detail oriented, change
crimped connections to soldered connections.

HTH,

JohnA in LA

 Rob Kleinschmidt wrote:

Get your jumper cables crossed?