Hey all!

My 77 280z alternator and/or regulator have decided to go to Valhalla. I have a 280zx parts car with a good alternator so want to upgrade to the zx alternator which is internally regulated and delete the original external regulator.

I've read all the DIY posts (which are all really well written) and am a little bit stuck. I'm seeing conflicting info on two of the best sites and wondering which is correct. I'm attaching pics from each site and pics of my connector in two configurations. Which is correct?

I chopped off the regulator plug to keep keep the car-side harness intact so the colors don't necessarily jive (I think I had an aftermarket regulator hence the wire color differences), however the pin number should coincide. There's two options:

Jumping 1 to 5 and 3 to 6 OR

Jumping 1 to 5 and 2 to 3

I'm guessing both might be correct but one operates the charge gauge/light correctly?

Any help here is much appreciated!

@SteveJ

Not sure you should have cut the original harness without having a back up plan to go back original. Understand it’s a little too late at this point. IMHO

Edited June 8, 20242 yr by Yarb
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Where are you seeing two options for 1977?  The writeup that you pulled from is specific to 1977.  His other comments are his best guesses for other years.  I'd follow his first set of instructions.

https://atlanticz.ca/zclub/techtips/alternatorswap/index.html

 

The table that you pasted might be from zcarcreations if I remember right (not positive).  That scheme will give you problems with your brake light.  Follow the atlanticZ instructions and you should be fine.  For 1977.

 

p.s. when you copy from other web sites it helps a lot to post the link.  Good luck.

1 hour ago, Yarb said:

Not sure you should have cut the original harness without having a back up plan to go back original

I didn’t. I cut that off the external regulator that I’m replacing. The female side (wiring harness side) is intact. 

45 minutes ago, Zed Head said:

The table that you pasted might be from zcarcreations if I remember right (not positive)

It is and they also base their instructions on a 77. 
 

http://www.zcarcreations.com/howto/voltreg.htm
 

I’ll follow the AtlanticZ instructions. Thanks!!

8 hours ago, sboy79 said:

Hey all!

My 77 280z alternator and/or regulator have decided to go to Valhalla. I have a 280zx parts car with a good alternator so want to upgrade to the zx alternator which is internally regulated and delete the original external regulator.

I've read all the DIY posts (which are all really well written) and am a little bit stuck. I'm seeing conflicting info on two of the best sites and wondering which is correct. I'm attaching pics from each site and pics of my connector in two configurations. Which is correct?

I chopped off the regulator plug to keep keep the car-side harness intact so the colors don't necessarily jive (I think I had an aftermarket regulator hence the wire color differences), however the pin number should coincide. There's two options:

Jumping 1 to 5 and 3 to 6 OR

Jumping 1 to 5 and 2 to 3

I'm guessing both might be correct but one operates the charge gauge/light correctly?

Any help here is much appreciated!

Jump 1 to 5 & 2 to 3.

I even found a source for the 6 terminal connectors to make a nice looking plug for the VR connector.

On 6/8/2024 at 3:05 AM, SteveJ said:

Jump 1 to 5 & 2 to 3

Just to follow up and close this out, I followed this direction and everything is working great. Thanks everyone!

On 6/8/2024 at 6:05 AM, SteveJ said:

Jump 1 to 5 & 2 to 3.

I even found a source for the 6 terminal connectors to make a nice looking plug for the VR connector.

Im stuck here. Installed 280zx internally regulated alternator. Stuck on what wires to jump together, alternator not charging....below is my voltage regulator plug wires. 77 280z...

Just follow the picture from the first post.

The white/black gets jumpered to the blue wire next to the white/red wire.

The white/red gets jumpered to the yellow wire.

The white/black wire goes to the alternator. It needs a switched source. In the internally regulated alternator, this is referred to as the L (lamp) terminal. The blue wire next to the white/red is a switched source, so it connects to the white/black wire.

The yellow wire goes to the alternator. It needs a constant source connected to the battery. In the internally regulated alternator, this is referred to as the S (sense) terminal. The white/red is electrically connected to the battery via a fusible link, so it has constant power.

I advise you to leave the engine harness side of the wiring intact. Cut the connector off the voltage regulator and jumper the wires on that side.

1 hour ago, SteveJ said:

Just follow the picture from the first post.

The white/black gets jumpered to the blue wire next to the white/red wire.

The white/red gets jumpered to the yellow wire.

The white/black wire goes to the alternator. It needs a switched source. In the internally regulated alternator, this is referred to as the L (lamp) terminal. The blue wire next to the white/red is a switched source, so it connects to the white/black wire.

The yellow wire goes to the alternator. It needs a constant source connected to the battery. In the internally regulated alternator, this is referred to as the S (sense) terminal. The white/red is electrically connected to the battery via a fusible link, so it has constant power.

I advise you to leave the engine harness side of the wiring intact. Cut the connector off the voltage regulator and jumper the wires on that side.

Something else must be wrong, I tried this and I’m getting 12.7V idling no accessories or lights on, I think that’s kind of low?

Yes, it's kind of low. However, you have all of us here at a disadvantage. We can't see what you did. (Hint: post a picture that clearly shows the wires you jumpered.)

To test things, follow this procedure.

1. Have the car off.

2. Remove the 2 pin connector from the alternator.

3. Measure voltage to ground at the yellow wire. It should read about battery voltage. It helps if you stick you probe into the back side of the connector.

4. Turn the key to ON. Don't start the car.

5. Measure voltage to ground on the white/black wire. It should read about battery voltage.

6. Report your readings in steps 3 & 5.

Here's an example of getting the meter probe on the back side of the connector.