i was driving my 70Z, and it started to sputter a bit at higher rpms, the tach was jumping around as it did. then i notice that the ammeter is pegged out at 45+ amps at anything above idle! the regulator was installed new in september 2012 ( from motorsport Z ), should this thing be bad already?? its reading 14V at the alternator, jumping to 17+ when i rev it. Any help would be appreciated.

Thanks,

Ken

Did you replace the alternator at the same time?

as indicated the alternator is putting out enough voltage, the sytem is overcharging, so I assume its the voltage regulator - replacing it this weekend.

as indicated the alternator is putting out enough voltage, the sytem is overcharging, so I assume its the voltage regulator - replacing it this weekend.

As indicated the alternator is putting out TOO MUCH VOLTAGE when the engine is at speed. That could be caused by a bad voltage regulator, a bad alternator, or it could be caused by someone matching an internally regulated alternator with a voltage regulator.

put in new regulator, everything looked fine - for about 5 minutes. ammeter back up to +35 amps at anything but idle. checked voltage at alternator - up to 17v when revving, but voltage at battery between 12-14V...

At first I thought it might be an internally regulated alternator. When did you get the alternator?

Edited April 5, 201411 yr by SteveJ

the regulator was installed new in september 2012 ( from motorsport Z ), should this thing be bad already??

There are a few threads from the past about the solid state MSA regulators. They were kind of sensitive, apparently, and failed quickly. Hate to say bad things about a sponsor's product, but not all of their products can be perfect. Your signs point to a bad regulator.

I bought one from "Checkers Auto parts" in Vegas 7 years ago. Still working. Think I paid around $20. I see they have gotten more expensive! Rock Auto has a Beck/Arnley for $18. You may want to try it.

You could use a regulator from a late 60s Ford if you don't mind rewiring the connector to fit.

the alternator has been on the car for 2 years with a regulator, i'm pretty sure its OEM without an internal regulator. again, I don't think a bad alternator will overcharge, past the regulator if its functioning correctly. Has anybody else had issues with the regulators from Motorsport Z?

Thanks,

Ken

drove it a bit today, ammeter was reading about +40 with the fan an lights on, needle started to jump around, now its reading exactly where it should.....

Note sure if this is pertinent, I have a 76 280z, I went through 3 alternators and 2 voltage regulators in about 2 weeks and never got the aftermarket alternator and the aftermarket voltage regulator to work properly. I had to upgrade to the new internally regulated alternator. No problems with over charging since.