[timbeam]

My battery was run down yesterday and after charging it up with the charger, the voltage at the battery with the engine running was just a little over 12 volts. Shouldn't the voltage with the engine running typically about 14 volts or so? My initial suspicion is the alternator, which is new, by the way. Could the regulator be effecting this?

1966 GT Convertible (see it at:http://www.geocities.com/tbeamguard/66GT.html)
1969 Sportsroof (which is For Sale, by the way)

 

[roadracer]

Probably the alternator? but could be the regulator. If you are using a "repro" regulator for authenticity I would change if first. I have had/seen many problems with these. There is a solid state "Motorsport" regulator available that is very reliable.

I would expect to see at least 14v across the battery when running.

Are you sure your battery doesn't have a bad cell. Check it with a hydrometer.

http://home.netcom.com/~jonescha/Photos/DCP_0355_178x109.jpg
"If you're under control you're not going fast enough"
Parnelli Jones
Try my website

 

[Guest]

Probably the regulator. It sounds like you must have just replaced the alt? Most parts stores can test both your regulator and alternator. You should show between 13.6 and 14.7 volts at the battery. If the alt and reg both test good the first place to start is to check all your grounds, battery to engine, engine to chassis, etc. Make sure all connections are clean and tight.

68 restomod coupe (sold)
69 Mach1
67 coupe - Son's

 

[Guest]

I would go with the regulator. Did you replace it at the same time as your alternator? It has been my experience to do them both at the same time so as to avoid problems. If you're not going for "Concourse" resto in shows, I would recommend an aftermarket "Mororcraft" unit. Good Luck.

Was Bob Emmerich on old forum

 

[Guest]

I just went through the same problem w/ a new alternator. It wasn't charging the battery at all as the circuit board in it was fried - after only 300 miles. I thought it was the voltage regulator, but took both parts to a local auto electric shop and he ran tests on both. It was the alternator. I had been charging the battery w/ a charger, then driving the car until the battery died (about 10 miles or so). I would shut it off after ten miles of driving, then it wouldn't start.

Just goes to show the "new" doesn't mean much when working on these old cars.

Doug

<img src="http://www2.dmci.net/users/dbowman/mustang1.jpg">

'66 signal flare red coupe with styled steel wheels
289 4bbl. w/ power steering, brakes, and A/C
White interior with a bench seat, deluxe seatbelt option, and an extra seatbelt in the back for my three kids . . .