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Daphur280

Alternator Upgrade Issue

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Daphur280    11

So I swapped a 83 L28et into my 73 240z, I went with the MSA voltage regulator diode plugin, and when I connect the battery a relay under the dash clicks on once.

 

I didn't think much of this as an issue until I discovered my alternator wasn't charging the battery. I cant seem to locate this relay in my wiring diagrams and cannot figure out if something is connected incorrectly aside from the alternator.

 

here is the relay that "turns on" when battery is connected

 

CopyofIMAG0030.jpg

 

another view:

 

CopyofIMAG0031.jpg

 

This is the connector that plugs into it:

IMAG0032.jpg

 

when I disconnect this plug and connect the battery, obviously it wont "click" however I'm sure the alternator will continue to not charge.

 

When I remove the MSA voltage regulator Diode Connector and connect the battery, the relay doesn't engage (or click)

 

Any help or ideas?? :(

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burninator    10

That's an interesting issue. I am not familiar with the MSA voltage regulator diode plugin. I just cut and spliced the wires and manually installed a diode following instructions on this page: Z Car Creations.

 

It worked pretty flawlessly for me. Is the alternator new? Are you sure it's good? If you can I'd check the L and S connections and make sure they have power when the car is running.

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Daphur280    11

That's an interesting issue. I am not familiar with the MSA voltage regulator diode plugin. I just cut and spliced the wires and manually installed a diode following instructions on this page: Z Car Creations.

 

It worked pretty flawlessly for me. Is the alternator new? Are you sure it's good? If you can I'd check the L and S connections and make sure they have power when the car is running.

 

This is my 3rd brand new alternator, I had it tested right out of the box to reassure that it will charge, so I'm confident that it works properly. The MSA diode plugin is just another way to wire in jumper wires and the diode without having to cut or splice wires in (Originally I did the splice and wire jump, and added the diode myself according to to this: Z Car Creations , however it didn't hold a charge then either, so I decided to eliminate my electrical mess and go with MSA's simple plugin).

 

As far as the L and S connectors, they both have power as the car is running...

 

So still stumpped.

 

 

I spoke to another individual and he mentioned something about the "Charge" light indicator needed to be addressed in the swap, because that was what the relay went to.

 

Another individual mentioned somehting about the factory Ammeter presents an issue if not bypassed during a swap.

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Daphur280    11

I did the same swap some time ago and just checked my notes to refresh my memory. On my 73 the fuel pump relay was always on after the swap. At that time I was only running a mechanical pump so I just removed it.

 

I have a turbo ZX fuel pump with a relay wired independently of the harness, so this is not the source of the problem with my car.

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Zmanco    13

I have a turbo ZX fuel pump with a relay wired independently of the harness, so this is not the source of the problem with my car.

Not sure I follow your logic. I experienced the same thing with my car after essentially the same mod (I made my own plug since MSA didn't offer it back then) and the issue was the factory fuel pump relay was always on. I removed it to solve the problem. When I later needed an electric fuel pump, like you, I created a separate circuit to power it. How do you conclude that it's not the fuel pump relay that's clicking on and staying on in your car?

 

FYI, I'm traveling so can't go look at the car, but I'm pretty sure the relay you show in the picture IS for the fuel pump.

 

Disclaimer: it doesn't matter to me whether this is or is not the issue - I just don't follow your logic.

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Daphur280    11

I created a separate circuit to power it. How do you conclude that it's not the fuel pump relay that's clicking on and staying on in your car?

 

I did the same thing, I wired in a relay to the pump, powered by the battery and it switched from a toggle switch. I meant to say "independant of the EFI harness" because I was still having issues wiring in the fuel pump relay harness with the EFI harness, so I wired it in with it's own relay and switch.

 

Hope that defines some of the logic and dismisses the confusion.

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Zmanco    13

I give up - I have the same year car as you, I did the same mod as you, and I experienced the same thing as you - a relay was always on when I reconnected the battery. In my case it was the factory fuel pump relay.

 

Yet because you have added as second relay to control the fuel pump you feel that the factory fuel pump relay can't be the problem. I STILL don't follow your logic, but that really doesn't matter.

 

Since you're sure that it's not the fuel pump relay, I'm very curious to see which one it turns out to be.

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Daphur280    11

Im sorry if I'm still not making sense here is how the "additional" or "new" Fuel pump relay is wired in:

 

12v constant > + battery

Neg > Ground

12v Switched > Toggle switch

12v to Source> directly to fuel pump

 

If that relay that clicks on inside the passenger side IS the original fuel pump relay, then it is not connected to the fuel pump that is installed as of now whatsoever.

 

So if by disconnecting the original Fuel Pump relay, this should no longer affect the charging system?

Edited by Daphur280

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NewZed    56

Im sorry if I'm still not making sense here is how the "additional" or "new" Fuel pump relay is wired in:

 

12v constant > + battery

Neg > Ground

12v Switched > Toggle switch

12v to Source> directly to fuel pump

 

If that relay that clicks on inside the passenger side IS the original fuel pump relay, then it is not connected to the fuel pump that is installed as of now whatsoever.

 

So if by disconnecting the original Fuel Pump relay, this should no longer affect the charging system?

 

It looks like you have two separate issues. Maybe the clicking, now unnecessary, fuel pump relay has nothing to do with your alternator not charging. If you disconnect the relay and you're still not charging, at least you can move on to other potential causes. Bad alternator, missing Lamp connection, etc.

 

Of course, you're using the alternator that came with the L28et, not the one from the old engine.

 

Just trying to give another perspective...

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Daphur280    11

I tested the alternator twice, before and after installation. Both times it passed. All connections are good and 12v and ground are present where it is needed. So I dont suspect the alternator is defective. And I was never able to confirm what that relay is amongst any wiring diagrams or connector diagrams, since the wiring colors do not match up. either way i took Zmanco's advice and unplugged the relay, it charges just fine now.

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napabill    0

I know this is a very old post and you have probably figured it out since then, but the MSA VR plug does not work on 1973 - 240/260Z with the electric fuel pump. The fuel pump is triggered by the old, external voltage regulator. MSA should be able to tell you what mods to make.

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