Voltage Regulator In Alternator

IMHO, you've probably got a defective regulator.
CAVEAT: If it's a 2 or 3 wire system (heavy output wire, a 'sense' wire & a charge light wire), then it's possible that the sense wire has a bad connection.

Don't confues the sense wire with a charging indicator light wire like the 308 BOSCH alternators have. Many 2-wire alternators are output & charge light, not output & sense.

Most alternator regulators work the same way.
If all else fails, There were some early alternators with external regulator boxes. One of these should be adaptable to your alternator. Sorry, I can't remember specific examples, last time I saw an external regulator alternator was back in the early '70s.

 

I agree with Verells comments.

If there is no sensing wire fault and you installed the new VR correctly (didn't ground out one side of the brush set by mistake in-case it's a ground switch circuit), then I'd look at another regulator or alternator complete. You'd be able to get a high quality bosch unit that would last forever to fit I'm sure, or if you just want an extenal regulator, I think the Bosch number for the solid state ones is (was?) RE55 and RE57.
Good luck

 

Is the 17V measured at the battery or the alternator output stud? If you have a bad ammeter, it may be signalling to the alternator a low voltage, making it charge higher.
I'd look closely at the ammeter before throwing the regulator you put in away. Ammeters are just voltmeters measuring voltage drop across a shunt. They are not very accurate and IMHO a PITA. Having all the cars current supply running to and from the dash and the to the supply/auxillaries builds a lot of V/drop up in the first place. (Dim lights etc...)

You could try bypassing the ammeter by running a heavy gauge wire to the battery directly form the alternator and see if that helps. (Providing the alt is internally sensed.) If it's externally sensed, check the sense wire Voltage matches your battery voltage within .25 volt as well as the extra wire.

Oh, and another thought, check all your ground wires too. The alternator is not rubber mounted is it? Check the chassis grounds as well.

Cheers