A Regulator Problem

[wxman1]

Several months ago I reworked my dash and installed an Autometer voltmeter among other
things. I noticed that the voltmeter frequently indicated 14-17 volts. The meter is connected
to the 12v unfused ignition slot on the fuse panel. The truck was running fine, but I always
wondered about whether on not the regultaor was defective. A couple weeks ago, a friend
of mine, who should know what he's talking about, told me that the 14-17 volts was not normal
and that the regulator probably needed to be changed.

So, off I go to AutoZone. The regultaor in the vehicle is basically a retangular metal can
with a relay and other electronics inside. The new regulator is about half as tall and is, apparently, solid state. The old regulator was electrically isolated from the radiator core
support that it is mounted to, so I did the new one the same way. However, the AutoZone
guy (who has not steered me wrong before) says the replacement regulator is supposed
to be mounted in contact with the core support (that it is NOT electrically isolated).

Anybody ever replace their regulator and run into this problem?

Jim
Mt Juliet

[86SILVERADO]

Well I just replaced my regulator. and I used the same screws with the rubber gromets but it has a factory ground wire going from the case right to the core support so it is obviously grounded there anyway. As far as the voltage being high that does not sound high to me especially if you have other loads on the system like stereo etc. A truck battery fully charged is actually around 14 volts and needs more when it has multiple loads on it like driving at night in the rain. I think your old voltage regulator was working just fine. Also my replacement regulator was identical to the old one which is why I buy my parts at NAPA as opposed to Autozone...... Just kidding....sort of.

[cdowns]

rubber grommets are more for vibration damage

[86SILVERADO]

Thanks CDOWNS, I figured they must be to minimize vibration considering the case was grounded.

[wxman1]

A bit of a brain fart. The original regulator had a black wire coming out of the
wiring harness that was grounded to the base of the old regulator. This is in
addition to the 4 wires in the black plastic connector. Well...the new regulator
had an extra tab on the bottow that I thought was a grounding tab...Ehhhh!...
wrong answer. I wasnt. The voltmeter was indicating between 11.0v and 11.8v
when it was connected this way. When I got a chance to work on it a couple
of days later...I pulled the black wire off this tab and the voltage instantly jumped
up to 13.8v and has been rock solid ever since.

Jim M.
Mt Juliet

[sKnNyPpY]

I know this is YEARS old, but did you ever figure out what that extra tab was for? Going through the same issues and about to chuck this damn alternator, unfortunately I just bought it and the regulator.

[Don Quixote]

Funny thing, digging up the old posts. About a year ago I actually switched to a 1 wire alternator despite what I had heard about them and I haven't had a single problem with it. That said, I rewired the truck at the same time with a kit that bypassed the amp guage so not I need to run a seperate volt guage which for me was fine since I can use the amp guage to measure the amps going to my trailer brake.

My point is that these days there is about no need to run the external regulator when the same alternator can come internally regulated.

That said, if I remember correctly, that last post was for the generator light on the dash which normally was never wired up with the guage package, just a random light on the dash that did nothing.