scooter123

this is what happens and low idle and lower speeds......any ideas of the cause....altenator getting bad????

oldspackrat

I don't know what year or model you have, but it sounds like a mechanical voltage regulator. If so, that is normal. The electrical ones eliminate this pulsation. My Rallye 350 does it & I find it kind of cool.

scooter123

Oh sorry..... It's my 1971 delta 88 royal

scooter123

Would this be my voltage regulator??

image_zps4afe15a0.jpg

tru-blue 442

Yes.

scooter123

How would I tell if its bad???? It looks newish to me but that don't mean it's NFG

oldspackrat

Use a volt meter to check the battery while it's running. If I remember right, the alternator should be putting out about +/- 14 volts while running. You might have to rev the engine up to about 1200rpm or so? Some times, if it idles really low, it might not put out that much. If it is not reading that, or if you don't like the pulsation, any parts store can get you a new one for $20.00-$30.00? or so?

oldcutlass

If your idle is too low it will do this.

BILL DEMMER

you could always upgrade your existing 10dn to a 10si internally regulated alternator, or 12si, or cs130, even a cs144. that's assuming originality isn't an issue.


bill

stellar

The CS130 makes for a nice easy upgrade. Bill Demmer may still have one for sale if you are looking. Ask him.

matt69olds

Best fix in my opinion!

jfb

I would also check the grounds.