costpenn

Still working out the bugs on my 72.

After 10 miles, gen. light came on. Yanked off the reman alt. and had it tested - checked out OK so I bought another USA made "analog" style regulator and re installed everything.

Now the gen light comes on at idle (750 rpm) but it goes off as the rpm's increase. As the gen light goes off, the interior lights actually dim a little. The regulator seems to be making a buzzing sound as the gen light goes off. Harnesses were all gone through, and belt tension is correct.

Thanks in advance for any help!

stellar

1st thing to check is the grounds. Make sure both alternator and regulator are well grounded.

hookem horns

X2 on cleaning grounds. Then check the voltage at the battery, even a $5 multimeter from Harbor Freight will do the trick. Post what you see engine off, at idle & at 2000 rpm. My charging system was working fine and replacing the connectors at the alternator and VR fixed my intermittent GEN light issue.

costpenn

Thanks - will post voltimeter readings tonight. I was wrong about one thing in my original post - the VR buzzing (funny how it sounds like the horn relay key buzzer) STOPS as the rpms increase and the light goes off.

Joe

costpenn

Ok - so went this morning to get battery voltage readings. Surprise! - light isn't going on, the VR's not buzzing. Still, here's what I recorded -

Batt Voltage - cold after sitting approx. 20 hours since last activity - 12.42

Batt Voltage - 30 seconds after start - RPM = 1200 - 15.33

Batt Voltage - 2 min. atfer start - RPM = 800 - 14.97

Any further info needed? I dont think this is going to be the last of this problem....

stellar

Voltage looks a bit on the high side. If the grounds are good I would suspect a problem from a group of 3. 1 bad v-reg 2 bad battery or low on electrolyte 3 low voltage at terminal#3 on the reg possibly a high resistance connection at or to that terminal. I would go after #3 first. To test you can run direct battery voltage to that connection and retest output.

hookem horns

I'm betting voltage regulator. You say you have an "Analog" VR that is sometimes buzzing and output is a little high, should be 14.5V. Service manual has directions for adjusting a points type regulator but I use a solid state one (Wells?) with no issues. Some folks like the originals but for < $15 might be worth a try.

Long time ago I saw a post where someone swapped the cap from an original Delco with a modern solid state one to preserve that original look. Not important to me but a neat trick.

costpenn

Dane,

Went back and swapped the "good" point type regulator for the "cheap" solid state regulator - problem fixed. Voltage at battery immediately after starting was 14.7, and gen light off. Thanks for the help.

BILL DEMMER

bear in mind that the voltage regulator adjustment is temperature dependent. the colder the temp-the higher initial charging voltage(within a range). a cold battery needs(and will tolerate) a higher voltage to start charging vs. a warm battery. at normal underhood operating temps. your voltage should be between 13.8-14.4 volts.

bill