Still alternator troubles.

[Andy Schuppert]

I connected up my "M's" alernator accordning to this site's diagrams. All was well, we were charging at 14 volts and I was happy. Then, I see we are reading 16 volts on the meter. After that it now reads consistently 12 volts.
Can anyone tell me why I would get up to reading 16 volts? Also, shouldn't the alternator always show 14 on the voltmeter?
Thanks, Andy

 

[Anonymous-0]

Hey Andy,
What's the problem? Maybe the battery was low in the beginning. If it was mine and I was getting "a consistent 12 volt charge", I'd be happy. Like they say, "Don't kick a sleeping dog"!

 

[Andy Schuppert]

Have you ever seen your pick up charge at 16 volts though??
So it's ok to only read 12 volts on the meter? If it is, I'll happily let this go

Andy

 

[old]

Check your battery voltage when the engine isn't running. You should get around 12.4 or so if charged up like it should be. Then check it again with the engine running. If its at or below what you got when not running then you have a problem and the alternator may be bad. If you get just the 12 volts then take it off and have it checked. Most places will do it for free.
Hobby farm

 

[El Toro]

I would check the charging voltage at the battery with the engine at 1/2 to 3/4 throttle. It should be around 14.5 volts. If you are getting 16 volts at the battery I think you have a regulator problem. Hal

 

[tn terry t]

yours wont be the first to be hooked up and then going south in a hurry it should read between 13.5 and 14.5 volts give or take a little your 16 volts told me the regulator went wide open the died

 

[Bob M]

Andy - Depending on the design of the internal regulator if the connection at the #2 (voltage sense) terminal on the alternator is lost it will cause system voltage rise to 16+ volts. If operated like for very long it can result in a complete failure of the alternator. Perhaps this happened in your case?

Suggest taking the alterntor to your local NAPA, etc. and have them put it on their test stand. If it turns out the alternator is DOA the cheapest fix is simply to replace it with a rebuilt.

Incidentally if the alternator is working correctly the voltmeter should read around 14 - 14.5 volts with the engine running...