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-   1st Generation Specific (1979-1985) (https://www.rx7club.com/1st-generation-specific-1979-1985-18/)
-   -   79 SA alternator upgrade (https://www.rx7club.com/1st-generation-specific-1979-1985-18/79-sa-alternator-upgrade-612132/)

KNONFS 01-08-07 08:28 AM

79 SA alternator upgrade
 
I have an 88 and a 91 alternator sitting around, and my father would like to upgrade his SA (50amp?) alternator.



I've search, but have not been able to find a step by step; on top of that it seems that if he upgrade the alternator, he will loose the volt gauge.



Would like to hear from people that have done this swap successfully, especially those that were able to keep the volt gauge functioning.

Whizbang 01-08-07 08:31 AM

if the 79 wiring is the same as say an 83, the S4 alternator would connect directly with no modifications. the S5 alternator (89+) requires a different connection.

ChasRX 01-08-07 09:22 AM

3 Attachment(s)
I did it with my '81; swapping out the stock (50amp) for an '89 second gen alternator (80 amp). I've yet to do it with a 3rd gen alt (100 amp?) that I have on a shelf in the garage. It was one of the best mods I've ever done for my electrical system. There's a couple of threads, here, with diagrams explaining how to do it correctly. There IS a difference as I used the second gen alt-plug connector. Let me see if I can find the diagram that I used on my other PC hardrive...

Ok, found these diagrams. I specifically used the first diagram; although, these guys did such good diagrams that I included all three. I may add that my 1st gen may sit without being driven for 2 or 3 weeks, and the battery is never dead. It always cranks. And, although I have a knife-switch on the positive terminal that I used to use when the car would sit for weeks (before this alt upgrade), I never have to worry about it, now.

KNONFS 01-08-07 01:32 PM


Originally Posted by Low Impedance
if the 79 wiring is the same as say an 83

My understanding is that the SA wiring is different to the FB.

KNONFS 01-08-07 01:34 PM


Originally Posted by ChasRX
I did it with my '81; swapping out the stock (50amp) for an '89 second gen alternator (80 amp). I've yet to do it with a 3rd gen alt (100 amp?) that I have on a shelf in the garage. It was one of the best mods I've ever done for my electrical system. There's a couple of threads, here, with diagrams explaining how to do it correctly. There IS a difference as I used the second gen alt-plug connector. Let me see if I can find the diagram that I used on my other PC hardrive...

Ok, found these diagrams. I specifically used the first diagram; although, these guys did such good diagrams that I included all three. I may add that my 1st gen may sit without being driven for 2 or 3 weeks, and the battery is never dead. It always cranks. And, although I have a knife-switch on the positive terminal that I used to use when the car would sit for weeks (before this alt upgrade), I never have to worry about it, now.

You are the MAN!!

We will check the wiring during the weekend; thanks for the info!!

BTW - On my 91, the 3rd gen alt was a bolt in work, no mods required (excpet for the custom pulley). Judging by that, if you already have a working 89-91 alt on your SA\FB, a 3rd gen should be a bolt in job.

rotaryB-2000 05-24-07 01:31 PM

i have a 1979 and need help!!!!

after connecting the two wires on the regulator and installing the main 12+ ignition to the top terminal on the back of the alternator..what do you do with the actual voltage regulator ? and what do you do with the remaining wires that are not crimped?

Siraniko 05-24-07 02:31 PM


Originally Posted by rotaryB-2000 (Post 6974021)
i have a 1979 and need help!!!!

after connecting the two wires on the regulator and installing the main 12+ ignition to the top terminal on the back of the alternator..what do you do with the actual voltage regulator ? and what do you do with the remaining wires that are not crimped?

unplug the external regulator and place 2 jumper wires as indicated below.
http://img.photobucket.com/albums/v3...r/DSC08575.jpg


Then you modify the stock alternator's pigtail. You only use 2 wires. Any unused wires, eliminate them.
http://img.photobucket.com/albums/v3...r/DSC08577.jpg

SunRedRX7 05-24-07 03:03 PM

Excellent pics on how to do the SA upgrade wackyracer. I've never been to good with text instructions on wiring things. I'll definitly throw my T2 alt that was in my 85 into my 79 tomorrow.

THANKS!

rotaryB-2000 05-24-07 03:15 PM


Originally Posted by wackyracer (Post 6974271)
unplug the external regulator and place 2 jumper wires as indicated below.



Then you modify the stock alternator's pigtail. You only use 2 wires. Any unused wires, eliminate them.
[/IMG]

this is great..now what wires go to tha alternator?
Sorry for the stupid questions but i purchased a 1979 with 1/ the wire harness missing.. i can track it from the regulator section of the harness.
And the 3 wire left on the plug ?

rotaryB-2000 06-18-07 10:06 AM

wackyracer..please help!!!!
this is great..now what wires go to tha alternator?
Sorry for the stupid questions but i purchased a 1979 with 1/ the wire harness missing.. i can track it from the regulator section of the harness.
And the 3 wire left on the plug ?

SunRedRX7 06-18-07 07:01 PM

1 Attachment(s)
The attached image shows how mine is wired up. Has worked since my last post in this thread.

The S connector on the alternator goes to a 12V source, I used the underhood Fuse Box/Fusible Links connector.

The L Connector goes to the White Wire/Black Stripe from the original connector, I gathered this from looking at other people's install pics. No charging issues so I guess its OK.

The other 2 wires I don't have hooked to anything from the original connector.

Latin270 09-11-07 10:07 AM

Sorry to bring back from the dead however I just realized my wire harness is very different that what I've seen in most of these posts. I think it was altered at some point. Can anyone post a pic of the actual pic of the stock alternator plug and where it goes to in the bay? Mine was blue yellow and black ??? All the write-ups say white/blackstripe and black/white stripe. Thanks for ANY help guys!

Siraniko 09-11-07 10:13 AM

Aldo,
in pix 1, the S5 alternator's extra wire connects to the loose wire shown in pix 2.



http://img.photobucket.com/albums/v3...r/DSC08564.jpg


http://img.photobucket.com/albums/v3...r/DSC06292.jpg

Latin270 09-11-07 10:36 AM

Wacky where does that wire start at? Any pics? I dont seem to have that b/w wire?

anbil25 02-02-18 06:25 PM


Originally Posted by Siraniko (Post 6974271)
unplug the external regulator and place 2 jumper wires as indicated below.
https://img.photobucket.com/albums/v...r/DSC08575.jpg


Then you modify the stock alternator's pigtail. You only use 2 wires. Any unused wires, eliminate them.
https://img.photobucket.com/albums/v...r/DSC08577.jpg

I need exactly this part of the whole conversation but the pictures wont work anymore. Is it possible to post them again? Thank you


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