New Voltage Regulator Issue (71 911)

[snapper911]

Hey guys,

Quick VR question. The car is a 1971 911 with the SEV Motorola Alternator (55 amp) and SEV VR. I recently had the alternator rebuilt and the VR tested...which was apparently not working. After some research I purchase a new Motorola VR (911-603-901-00-M262) from the host.

I hooked up the new VR as the picture shows below, which I believe is correct. Fire the car up and I get a reading of 12.5 V at the terminal no matter the RPM. I removed and installed the old (original) VR and am getting anywhere from 12.5 at idle to 14.7 at 2500 (which is why it needs to be replaced).

I hook the new one up again and same results, 12.5 no matter what rpm
.
Is the new VR hooked up correctly as per the photo below? Is this the correct one for my setup?
Also, I would like to have the original VR rebuilt...who is the guru I should send it to?

The car has:
- rebuilt alternator
- new factory ground straps throughout.
- new terminals and brand new battery.

Thanks for any assistance!

New VR



Old:

[timmy2]

Looks to be hooked up correctly,
Perhaps you just got a dud from wherever you bought it.
Your old one indicates the alternator is capable of putting out higher voltage, so I'd suspect the new one as DOA...

Pop the old one open and see if you can detect what has failed. I don't know who fixes them.

[snapper911]

Thanks,
I purchased it from Pelican about a week ago so its fairly new...maybe a bad batch.

[timmy2]

The only other thing I can think of is perhaps try adding a ground to the brown center wires as the case is normally grounded on the old one. Maybe this one needs a better ground reference.
Run it to a mounting screw for the aluminum panel somewhere.

[wwest]

The "key" is: How much voltage drop do you get across the battery posts at ~2500 RPM as you add load, headlights, blowers, etc.

[wwest]

Originally Posted by snapper911

Hey guys,

Quick VR question. The car is a 1971 911 with the SEV Motorola Alternator (55 amp) and SEV VR. I recently had the alternator rebuilt and the VR tested...which was apparently not working. After some research I purchase a new Motorola VR (911-603-901-00-M262) from the host.

I hooked up the new VR as the picture shows below, which I believe is correct. Fire the car up and I get a reading of 12.5 V at the terminal no matter the RPM. I removed and installed the old (original) VR and


am getting anywhere from 12.5 at idle to 14.7 at 2500

That's 'way too much voltage variation at a consistent 2500 RPM unless other parameters are involved. Bouncing or inconsistent voltage measurements at different time...??

(which is why it needs to be replaced).

I hook the new one up again and same results, 12.5 no matter what rpm
.
Is the new VR hooked up correctly as per the photo below? Is this the correct one for my setup?
Also, I would like to have the original VR rebuilt...who is the guru I should send it to?

The car has:
- rebuilt alternator
- new factory ground straps throughout.
- new terminals and brand new battery.

Thanks for any assistance!

New VR



Old:

[snapper911]

Perhaps I didn't explain correctly in my original post.

I am getting 12.5 at idle and up to 14.7 at roughly 2500 - 3000 RPM. This is on the old VR which was tested and deemed to be faulty....thus the replacement.

Alternator keeps up when I turn on headlights, blower...etc on old VR.