I am trying to replace the original voltage regulator with aftermarket because the test indicated this was the problem. The issue I am having is the aftermarket part from either O'Reilly's or AutoZone has a pigtail.connector with 4 tines. How do I connect the new part? There are no instructions.

 

I see a picture of the horn relay / junction block.

 

Okay so my ignorance is obvious. So where is the voltage regulator located

 

On the firewall, slightly off-center towards the passenger side.

 

Let’s start with model/year first.

Second, how could you run any test or diagnostics without knowing where the suspect components are?

To answer your question, the voltage regulator is on the firewall above the distributor If it’s a 69 or newer 442 the regulator is built into the alternator.

 

The pigtail wiring is in case yours is burned up and needs to be replaced. It yours is OK, then just plug your connector into the new regulator.


This post has pictures of the regulator:
https://classicoldsmobile.com/forums...lass-s-159376/

 

I had the alternator tested after needing a jump and disconnecting the negative on the battery when I got home, charged it. Disconnecting the battery killed the car. I took it to O'Reilly's and had the alternator tested.


This is behind the brake booster
It's a 71 Supreme

 

There is nothing like this on the firewall or anywhere else under the hood that I could see

 

Donald, please show us pictures of your alternator, specifically the harness.

 

Makes sense. It could have an internal regulator. I'll send one tomorrow.

 

Consider performing a Search on this site using the terms: 10SI, 12SI, CS130 & 10DN. This will assist in garnering both visual & logical information regarding external vs. internal VR alternators. You'll be ahead of the game when it comes time to deciphering what ALT and type of wiring you have for discussions moving forward.

 

The left one is internal, the right is external.

 

In 1971 GM alternators went with the internal regulators.. In 1970 that was as split year for GM, some had internal as well..

 

I think mine is external. There is only the bolt connection.

 

Yours is internal, it has a 2 wire male connector on the top side not the back side..

 

Correct, "if" the ALT is original. That is why it's important to determine if the ALT is original, aftermarket &/or re-wired.

 

I posted too soon.

Exception: A real 1971 442 came with the open face, "diamond back" 10SI internally-regulated alternator while all others came with the 10DN externally regulated alternator. Always the possibility the ALT has been changed out by a PO.

 

That simplifies things. I believe it has a lifetime warranty from O'Reilly's.

 

Make sure you ck the voltage @ the battery or back side of main plus wire to alternator with the lights on at 1000 rpm's, you should get a reading from 13.8 to 14.5 volts. good luck glad to help you...

 

Uh, the alternator is not hooked up?

 

I know, after it is hooked up ck this. Didn't think i needed to state the obvious..

 

Was responding to the picture, not your post.