To all our electrical wizards out there....

Over the past week or so I have noticed that when I start her up the voltage starts off negative on the dash gauge.

With the flukemeter on the battery while it is in the negative zone the meter is reading 12.06 to 12.1, 12.2.

If I rev the engine up to over 2,000RPM's it will climb up to over 14.3, 14.4Volts (Normal).

This has happened with and without a load (Heater or other current drawing accessory)

Sometimes it is just normal with no indications of discharge.

I believe this has something to do with the Alternator....Specifically the regulator portion of the alternator unit.

The CAT has just over 100K miles and is in Great Shape. Just finished a 4K Road Trip with no issues.

With regards to the Alternator, am I on the right track? and should I consider replacing the Regulator or rebuild the unit?

I believe this Alternator puts out ~ 75amps. I know you can purchase units that put out over 100amps.

As always your insight is appreciated.

Softball 60/Paul

 

Alternators usually live about 100k miles/160 km before a rebuild is suggested. They can live longer. I'd just give it an overhaul. New bearings, regulator and a new capacitor and you should be good for another 100k miles.

 

Hi, a slipping or loose belt can cause that however, more often in my experience it's the regulator. On many of my cars I've replaced the regulator easily and to great affect, but with my Jag and it's age I had the alternator totally rebuilt locally in a day($160 CDN), in your case I would agree with Diam and have the whole alternator rebuilt - it's over due and a potential failure on the horizon...