hooked up a set of bosch gauges i just bought new for my 1972 cutlass .it shows i have good oil pressure ,temp stays right at 190 once its warmed up but my amp guage needle surges between 13 and 17 amps while idling you can see the interior lights get real bright when it jumps to 17 i have a brand new 60amp three wire alternator .belt is nice and tight cant firgure out why it would do this .any thoughts?

 

do you mean volt gauge? Sounds like a defective alternator.

 

yeah sorry its a volt meter

 

i thought it might be i have my old one i could install and see if it operates normally .

 

Is this an internally or externally regulated alternator, and if external, is the regulator mechanical or electronic?

- Eric

 

its internal regulator

 

Double check all your connections, including the small red (sensor) wire, but if they're all good, there's a good chance it's a bad regulator inside the alternator.

You can change just the regulator, and they're not expensive, but if it's a new alternator, best to just take it back.

- Eric

 

If its jumping to 17v you have issues. It points to a bad internal vr is the culprit.

 

thanks guys ill look for my reciept and bring it back im sure they'll test it .hope i can find it now, bought it several months ago .what is it with brand new parts these days ?its the old one step foward two steps back routine im kind getting used to it now

 

Brand new Chineesium alternator. Rebuild your old one.

 

Five letters: C-H-I-N-A.

Don't worry - the guys in Anderson, Indiana who used to make top quality alternators all have good jobs at Wal-Mart now.

- Eric

 

i took off the alternator and returned it no problems at napa cant get a new one till noon time .i got some time to kill so i think ill dig out my old one and try it .the new napa alternator did have made in usa stamped in it (just an elaborate ruse i suspect).if i were to keep the old one how would i clean it up? its nearly black im afraid if i start wire wheeling it i might clog something up inside it ?

 

Dismantle, clean each part, re-assemble.

It's not that bad of a job. Takes time. Think how much time you have into the current setup.... which stil doesn't work right.

 

Carb cleaner, a rag, and a tooth brush ought to clean it up nicely.

 

no such luck with the new alterator changed it out with a replacement and does the same thing .there has to be a short or something elsewhere. started disconnecting fuses to maybe isolate the issue no luck so far .and i believe i ran it out of gas .enough for one day ,time for a cold one and forget it for a while.

 

Did you check the connection of the sensor wire, as mentioned earlier?

- Eric

 

i checked all the connections going to the alternator not sure what you meant by small red sensor wire .i havent got under the car to check starter wiring yet

 

Is yours wired like this? It originally was an external regulator.

 

sorry i didnt get back right away .it looks like thats the way it is

 

Yours is an externally regulated alternator, the culprit to your issue is probably the VR (the black box). It can ve replaced with the same type or a solid state one, PN VR715.

 

So everything in this thread after Post #5 is invalid because when I specifically asked you whether your alternator was internally or externally regulated, you said it was internal.

You have a mechanical external regulator. As I would have said a couple of days ago, this is a common failure mode for these. As Eric says, replace it.

Forgive me for being a p*ick (or don't) - I'm having a rotten Sunday daylight savings morning at work.

- Eric

 

thanks eric i apologies for giving the wrong info i just dont know enough about the electrical systems .i also apologies to the folks at napa and the chinese . is there a way of testing the regulator ? and should i replace that little condensor looking thing that is attached to it .i get it md im off today and still having a bad day the biggest reason a lot us look to you guys for answers is because we simply don't know .lesson learned

 

The capacitor is for am radio interference and is probably still good. It is not required on the VR715 regulator.

 

The mechanical regulators can, technically, be cleaned and adjusted, and for that reason, I'd recommend keeping it, rather than throwing it out, as it may be worth something one day.

That being said, you can buy electronic replacements that work better and may be more reliable (compared to modern replacement mechanical regulators anyway), for something like $20, so I'd just go get a new regulator, plug it in, and call it a day.

And, hey, I can't really blame you. The guys at the auto parts store, on the other hand, should have asked you about the regulator right away when you brought the alternator back, since that is an externally-regulated alternator. THEY didn't do their job.

- Eric

 

picked up the new regulator today and installed after work everything seems pretty normal was charging around 15 with a weak battery.still have an ever so slight flicker in the interior lights i need to track down .i have had the brake light on in the dash for a while i thought it could be shorting somewhere . the e brake switch is working fine but when i unplugged the wire from the brake ditribution block the light goes out .would this be a ground issue or a bad distribution block .will have to dig deeper tomorrow .btw i did bleed the brakes and have a pretty firm brake pedal .

 

All the mechanical regulators do that.


When you bled the brakes, you pushed the piston in the distribution block off center, activating the warning light.

Now you've got to open a bleeder on the other side of the circuit and jam down on the pedal to push it back.

- Eric

 

ok thanks ill give it a try

 

Glad it all worked out for you.

 

I love reading you guys posts.

 

just to update the bleed and stomp method turned the light off thanks again guys .