I bought a new battery last week. The dash volmeter read 8 vs. 16 as it normally does. Could it be my alternator or voltage regulator? Where the heck is the voltage regulator? Any thoughts?

Just had my alternator rebuilt in my 88 raider. It was showing the same symptoms as yours until the voltage went out commpletly. The voltage regulator is built into the alternator.

Papadanny is right, the regulator is built in to the alternator... you'll need a new one. I've replaced an alternator on my '89 due to a failed regulator and the symptom was overcharging, bright lights and a pegged voltmeter. The alternator is very powerful for quick charging... the regulator is really a constant voltage limiter if you want to look at it that way. On the same note, if your battery was weak, close to dead, you'd probably see a bit higher than normal readout on your voltmeter as the regulator would allow more current through to get it charged up. Have you checked the battery/alternator with a tester? I guess it could also be a bad gauge, but I'd think that the draw/output of the new battery was a bit of shock to the system and you blew a diode or two (I think there's a total of 3 and somehow they add up to the total voltage output of the alternator).

If there's a good charge on the battery for now, go to Pep boys or Auto Zone and have them test... they'll spot a bad alternator. Just don't buy a replacement there unless you want to replace it again soon.

I had the same thing happen on my '91. I didn't want to spend food money on an alternator so I took it apart and replaced the regulator (after ruling out everything else, of course). If you can solder and have a good hot soldering iron, a multimeter and a test light, it's not too hard to do, and it only cost $34.00. If the truck is your daily driver you may want to put in a new alternator. With key on / engine off, does your battery light in the dash come on? Often times when the battery light never comes on w/ KOEO, it's an indication that the regulator is bad.

Just rebuilt mine same problems- $85.00. Good as old <img src="/forums/images/graemlins/smile.gif" alt="" />