40 minutes ago, SteveJ said:

What white/red isn't connected? A photo or two would help. If your alternator isn't getting the sense voltage it would overcharge, just as @Captain Obvious said.

I took a look at the FSM just now and it appears that the W/R bullet connector that isn't connected is for the condenser but on remans these days, the condenser is pre-connected to the alternator's B-post using a ring terminal instead of an external bullet connector so it just dangles

Edited July 3, 20231 yr by chaseincats

Just to be clear, you have to alter the wiring so that you have this:

That is usually accomplished by jumpering the WB to BW at the voltage regulator and jumpering the Y to WR at the voltage regulator. Those are the voltage measurements we have been talking about.

1 minute ago, SteveJ said:

Just to be clear, you have to alter the wiring so that you have this:

That is usually accomplished by jumpering the WB to BW at the voltage regulator and jumpering the Y to WR at the voltage regulator. Those are the voltage measurements we have been talking about.

Since this car is a '78 it is the only 1st gen year that doesn't have an external regulator and uses what became the ZX alternator

So what is the voltage at those two points?

Uh-Oh. Now I'm worried that we're getting caught up with potential mistakes in the documentation and discrepancies in wire colors.

When I was saying there are two W/R going to the back of the alternator, I was operating from this:

And that's clearly different than the pic from the 78 manual posted above.

So @chaseincats, what color wires do you have going to the two position spade connector on the back of your alternator? Here's a pic showing the connection layout:

 

1 hour ago, Captain Obvious said:

Uh-Oh. Now I'm worried that we're getting caught up with potential mistakes in the documentation and discrepancies in wire colors.

When I was saying there are two W/R going to the back of the alternator, I was operating from this:

And that's clearly different than the pic from the 78 manual posted above.

So @chaseincats, what color wires do you have going to the two position spade connector on the back of your alternator? Here's a pic showing the connection layout:

 

The wire colors differ from my 78 FSM which is interesting but it looks like @Captain Obvious's is more on point.  I've attached a picture of my alternator's wiring (I unplugged the T connector for a better view of the wire colors).

E: Black wire

B: White with red stripe wires (condenser's WR has been connected to the terminal via a ring terminal instead of the original bullet connector)

S: White with red stripe

L: Blue with white stripe that becomes blue with black stripe after the electrical tape I think (the wires are dirty so it's hard to see) 

Hijack attempt!

I swapped in the Frontier alternator into a friend's 77 this morning. Here's the jumper I made at the voltage regulator using a 4-pin Yazaki connector I purchased from Eastern Beaver.

It's a nice water-resistant connector, and it's period appropriate. If he ever decides to go back to original, I can reverse the work, too.

Edited July 3, 20231 yr by SteveJ

Just now, SteveJ said:

Hijack attempt!

I swapped in the Frontier alternator into a friend's 77 this morning. Here's the jumper I made at the voltage regulator using a 4-pin Yazaki connector I purchased from Eastern Beaver.

It's a nice water-resistant connector, and it's period appropriate. If he ever decides to go back to original, I can reverse the work, too.

Did you need to do any hardware modifications to the alternator housing or mounting brackets?  I know most non-Z alternators need that which I'd like to avoid if possible.

1 minute ago, chaseincats said:

Did you need to do any hardware modifications to the alternator housing or mounting brackets?  I know most non-Z alternators need that which I'd like to avoid if possible.

The only modifications I needed to make were wiring related. I had to put a bigger ring on the wire for the B terminal. I put a 2 pin connector on the pigtail for the Frontier alternator to connect the S & L wires, and I had to de-pin 4 wires from the VR connector (only needed for 74-77) to jumper the wires for the S & L terminals.  Oh, I did need a longer bolt for the front alternator mount for some reason. Otherwise, it fits like a glove.

21 minutes ago, SteveJ said:

The only modifications I needed to make were wiring related. I had to put a bigger ring on the wire for the B terminal. I put a 2 pin connector on the pigtail for the Frontier alternator to connect the S & L wires, and I had to de-pin 4 wires from the VR connector (only needed for 74-77) to jumper the wires for the S & L terminals.  Oh, I did need a longer bolt for the front alternator mount for some reason. Otherwise, it fits like a glove.

Could you send me where you got the alternator/2-pin connector?

I'd like to keep working on getting the current one working properly since the theory so far is my car's wiring is the issue but that sounds like an upgrade I'd like to make later on

All of the details are in post #4 in this thread.

11 minutes ago, SteveJ said:

All of the details are in post #4 in this thread.

From the pic on the rockauto part page it looks like I'd need to yank the fan off of my current alternator and transfer it to the new one somehow, no?