Car is a '74 2.0L

Driving along the beach road this evening I noticed my center console volt meter reading about 12V. Thought it was normal as I had the lights on however, further along it started to drop even more and by the time I stopped at a light it was near 10V. The charge idiot light never illuminated.

So, checked the ALT belt - good tension
Battery engine off - 12.2 V
Battery engine running at idle - 13.5 V
(used a hand-held VOM)

Then I touched the case of the voltage regulator - EXTREMELY hot. Hotter than anything else in the engine compartment.

Do I have a bad voltage regulator? Can something else cause a voltage regulator to overheat?

Don't know how old the regulator is, but it looks old. Alternator replaced one year ago. Center console volt meter less than 3 months old and has been displaying normal readings until now.

Input appreciated.

Ansbacher
Seminole, Florida

Not sure about normal. Probably a regulator gone bad. My experience has been that it is common for new regulators to under deliver under load. It seems it is trial and error. Once the headlights are on the regulator sometimes has trouble keeping up. Evenentually I went with an adjustable regulator. In your case I hope a new one will do. Check out the pelican site for a nice diagnostic to evaate alternator vs regulator. It is in the 911 area.

Stock Bosch or Aftermarket?

Mine that got hot is a Bosch Number - 0 190 601 006 but it says Made in Brasil.

Ansbacher

[/quote]
Not sure about normal. Probably a regulator gone bad. My experience has been that it is common for new regulators to under deliver under load. It seems it is trial and error. Once the headlights are on the regulator sometimes has trouble keeping up. Evenentually I went with an adjustable regulator. In your case I hope a new one will do. Check out the pelican site for a nice diagnostic to evaate alternator vs regulator. It is in the 911 area.
[/quote]

Any tips when installing the adjustable VR ? Just ordered one from Dave's

I had the same with my original Bosch regulator. Voltage dropped off to the point that when I pressed the brake pedal the brake lights came on and the voltage dropped around 9V and engine stalled.
I discovered that the regulator casing was VERY hot, too hot to touch.
I got a new Beru one that was 1/4 the price of a Bosch unit. Slightly shorter on height (which makes fitting the relay board cover much easier on a 74 car)
It's solid state modern inners so runs stone cold to the touch.
They're common to the VW T2 bus (with Type IV engine) so you can purchase them at most VW suppliers. or off ebay

http://www.ebay.com/itm/BMW-E10-1600-2002-...dae&vxp=mtr

As regards tips on fitting...

Just two tiny screws in the side and it pulls up and out.
Plug and play.

Darren C - Thanks for confirming my problem! I have ordered a new VR today.

Ansbacher