voltage reg problem

[MacataQ]

GOOD DAY ALL
i have spent the day going thru a ton of posts on Voltage Regulators
and i cant seem to find anything that covers my specific problem. hoping someone here will set me on the correct path electrically (pardon the pun)
1972 c10
SBC 350
3 wire alternator w external Voltage Reg
no A/C no pwr win, stock radio
details
low charging voltage @ bat when go thru stock reg -by pass reg (test) alternator pitting around 14.9 15.4v
i believe this test confirms the alt is okay?
so i suspect the VR
so went online Napa Canada out in my vehicle details and was directed to
purchase VR142SB as exact fit for my truck, so i ordered it.
when i got it a became perplexed
i thought it would be a matter of plug and play .."as in EXACT FIT"
but it doesn't look like it to me
see pics
any ideas?
thanks
Mac

['68OrangeSunshine]

Originally Posted by MacataQ

GOOD DAY ALL
i have spent the day going thru a ton of posts on Voltage Regulators
and i cant seem to find anything that covers my specific problem. hoping someone here will set me on the correct path electrically (pardon the pun)
1972 c10
SBC 350
3 wire alternator w external Voltage Reg
no A/C no pwr win, stock radio
details
low charging voltage @ bat when go thru stock reg -by pass reg (test) alternator pitting around 14.9 15.4v
i believe this test confirms the alt is okay?
so i suspect the VR
so went online Napa Canada out in my vehicle details and was directed to
purchase VR142SB as exact fit for my truck, so i ordered it.
when i got it a became perplexed
i thought it would be a matter of plug and play .."as in EXACT FIT"
but it doesn't look like it to me
see pics
any ideas?
thanks
Mac

Does the 4-Contact plug fit?

It looks like a slight design change. The contact on the left [in both pix] goes thru a heat dissapating resister to ground on the box itself. In the newer version, there's a terminal for you to attach your own ground lead.
The Factory also had the VR boxes suspended off the Radiator Core Wall with vibration shedding rubber mounts. I have duplicated this effect by stacking rubber plumbers' washers and this may isolate the VR Box from ground, so groundibg is necessary.

To be honest, I had trouble with ''Lifetime Warranty'' replacement parts from O'Reilly's. They bought out Checker Auto and inherited their lifetime warranties, but their replacemts all failed. On my '68 Chevy Stepside, I cannibalized a VR that was on my '67 K/10 Suburban, from 1998. It works fine.
On my '71 GMC Jimmy, I got a wiring conversion kit from M&H, and Got a NIB SI-12 Alternator with internal VR. It's working fine.

[MacataQ]

orange
thanks for responding
it looks like it lines up correctly
the new one does not have aground on the casing like the old one
Mac

[1970 CST Short Wide]

I seem to remember something about polarization of a VR. Touching one of the wires to get it flowing in the right direction. "??????????

[MacataQ]

70
not sure on that? any details?
Mac

[Already Gone]

following

[1970 CST Short Wide]

Originally Posted by MacataQ

70
not sure on that? any details?
Mac

This was a long time ago. I remember something about touching Field to Ground. Probably long forgotten due to new Alts with built in Reg ?????
Any body old enough to remember this or am I Dreaming. LOL
I’m only 70 and I think my mind still works OK. ????

[Rust_never_sleeps]

Originally Posted by MacataQ

....
it looks like it lines up correctly
the new one does not have aground on the casing like the old one
Mac

Isn't the L-shaped contact on the left spot welded to the case, or is that an optical delusion?

[1970 CST Short Wide]

I’m going to laugh my Ass off if I’m correct here. Do your research, let me know

[MacataQ]

Originally Posted by Rust_never_sleeps

Isn't the L-shaped contact on the left spot welded to the case, or is that an optical delusion?

i have attached another pic hope it shows the L shaped contact better.
im not any better a photographer than electrician!
Mac

['68OrangeSunshine]

Originally Posted by Rust_never_sleeps

Isn't the L-shaped contact on the left spot welded to the case, or is that an optical delusion?

It looks like its separated from the rest of the case by a sheet of black plastic. The tip of the L-shape is a male spade terminal for a ground lead with a female spade terminal, a length of wire, and a ring terminal to be connected to the frame or chassis somewhere.
All the VRs I've gotten have a selftapping machine screw w/ 1/4'' hex head that grounds the VR.
As I said earlier, because the rubber mounting grommets isolate the VR from road vibrations may also isolate it from Ground.

['68OrangeSunshine]

Originally Posted by MacataQ

i have attached another pic hope it shows the L shaped contact better.
im not any better a photographer than electrician!
Mac

OK. I guessed right.
That's for a Ground lead.

[MacataQ]

Orange
yes all the contacts seem mounted on the black plastic piece. so i am assuming that L shaped one is going to be the brown wire on the original VR, using the original female
plug.
thanks for responding
Mac

[RustyPile]

Originally Posted by 1970 CST Short Wide

I seem to remember something about polarization of a VR. Touching one of the wires to get it flowing in the right direction. "??????????

This procedure was for polarizing a generator.. Back in the days, some car manufacturers had positive ground systems, others had negative ground systems.. Polarization procedures are not necessary for alternators.

MacataQ, now is your chance to upgrade your charging system. Unless you just want to keep things exactly original, you can install an internally regulated alternator.. Minor wiring modifications and you're in business.. How to do this simple procedure is all over the internet, including our own ELECTRICAL forum.

[MacataQ]

Originally Posted by RustyPile

This procedure was for polarizing a generator.. Back in the days, some car manufacturers had positive ground systems, others had negative ground systems.. Polarization procedures are not necessary for alternators.

MacataQ, now is your chance to upgrade your charging system. Unless you just want to keep things exactly original, you can install an internally regulated alternator.. Minor wiring modifications and you're in business.. How to do this simple procedure is all over the internet, including our own ELECTRICAL forum.

Rust
thanks for the clarification...good to know!
i have the wiring diagram to switch to internal alt for later when i can afford to do that, but since this alternator tested fine & already bought new VR, ill keep using it.now i understand how the whole thing works! installing tm...er today, will report results
thanks
Mac