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Got amps? GM Alternators! (pics and part#'s added)

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I ran a 90A GM alternator on my GL-10 last year. It was easy to install and better, cheaper, readily available part. I'll be doing the same thing for my RX this year. I like the 74-82 or so models.

 

I have pics and diagrams for this if anyone is interested, drop me a line.

-Chuck-

  • 1 month later...
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yes, I am reviving this old thread, but I need info

 

has anyone done the conversion with the P7157 alt that has A/C yet? My A/C uses the big Hitachi compressor that mounts inside the bracket, so theoretically I should not have a clearence problem (SPFI, so intake is not an issue), but I can't afford to spend the money to buy the alt and be wrong. I could also use the measurements of the alternator's dimensions to figure out i if it will fit if anyone has them. Any info about it period would be very much appreciated.

 

Thanks

i contacted parts america and this is what they sent me.

 

 

Your Palladium P7157 alternator fits the following vehicles:

 

BUICK

1977 CENTURY ..................

 

Now that's good info for those of us using JY Autoparts Inc. Thanks Mike.

 

I concur with Tin Soldier about the ea82 a/c issue. Probably world work with any inboard mounted a/c - both Hitachi and Matsus.h.i.t.a/Panasonic - but might not with the outboard mounted a/c - which is limited to the Matsus.h.i.t.a/Panasonics and I think is how the dealer add-on a/c's were installed. I have an '89 with the (dealer installed) outboard a/c. If someone will tell me the case diameter of the P7157 alt., I'll check it out. Other wise, I'll try to pick one of these alts up on my next visit to JY.

I no longer agree with Tin Soldier about the outboard mounted EA82 alternators!

 

I had a few minutes this morning to stop by my local JY Autoparts store to check out the P7157 alternator situation with regard to SPFI EA82s (didn't check any turbos).

 

I'd caution you all that I didn't have enough time to really evaluate this, but the following is my first impression. (So don't spend any money on my say so at this point - check it out yourself).

 

I found the alternator on a Caddy - WOW! is that a monster - and took some measurements.

 

Sadly, I don't think it will easily fit on an EA82 with the inboard Hitachi a/c compressor. Mostly this is due to the fact that both the alternator pivot point and the belt tension adjustment arm for the stock alternator are part of the a/c comp mount casting and thus have a fixed distance between them. The alt pivot point is also at the top inboard of the alternator instead of below the alternator which limits the amount of usable space. There is no easy way to increase the distance between the alt pivot point and the adjusing arm. I think there is enough (just) physical space between the a/c and the battery for the GM alternator to fit, but you'd have to probably cut the old belt tension adjust arm off the casting and fabricate a new one. The GM alternator case would also come awfully close to the water pump inlet pipe, but I my eyeballs tell me it would clear it - but my eyes aren't what they uesed to be!!

 

I don't think there is any way at all that the GM alt could be used with an outboard mounted a/c compressor (inboard alt). There is just not enough room between the a/c compressor and the power steering pump. There may be a solution to this, however (I have this configuration on my wagon and would really like a bigger alt.). See below.

 

I couldn't find a Subie with an inboard mounted Matsus.h.i.ta/Panasonic compressor so I don't know about this case. If the stock alternator in this configuration has a pivoting sloted arm (unlike the case with the curved cast in arm on the Hitachi), it would probably fit though you might have to fab a longer pivoting adjusting arm which should not be very difficult.

 

Which brings me the a possible solution for the outboard mounted a/c compressor. If the preceding paragraph turns out to be true, then you could get the mounting subframe and a/c hoses and move the outboard mounted a/c compressor inboard and have room for the GM alternator outboard. Of course replacing the a/c hoses would mean the a/c would have to be recharged, but that can be done for less than $50 and be changed to R134a while you're at it (I just did the conversion on a friends Subie with a bad a/c compressor - nothing to it).

 

Stay tuned, I don't know when I'm going to have time to persue this, but I would really like a bigger alt on my wagon. So I'm going to keep at it until I either find a way to do it or decide it's too much trouble.

  • 2 months later...
I

I don't think there is any way at all that the GM alt could be used with an outboard mounted a/c compressor (inboard alt). There is just not enough room between the a/c compressor and the power steering pump. There may be a solution to this, however (I have this configuration on my wagon and would really like a bigger alt.). See below.

 

What if I didnt have a power steering pump?

The GM alternator DOES fit with inboard A/C compressor, I'll do it again on my RX and post pics and maybe whip up some brackes to sell on here to make it simple.

i have my 105 amp alt from an 89 chevy astro and i still have the ac on my car(or at least the compressor. and the only thing i had to do was make a small bracket to extend the bottom 1 a little further out, which a timing belt tensioner arm with the roller part removed worked perfectly for. and other than a misswire at first i have had no problems with it at all and it handles every bit of drain i can put on it at once, at idle. and i have an inboard mounted ac compressor. not sure what model alt i have but heres a pic of it installed.

 

IM001269.jpg

 

 

i do however need to get around to removeing 1 of the spacers in the pully as it sticks out a hair too far and slightly wears on the belt

  • 2 months later...

back from the dead,i don't have pics,but after a year i finally did this swap.i wanted to find the 80 amp alt so that i could fit it without messing up the air cleaner.i followed the write up to a t and it was right on.i did need a little more taken off the ears,and made a small bracket for the adjustment bracket.but i was able to maintain my stock belt....it was a *************** gettin that belt on , but once it was on it did need tightening.my multimeter resukts follow:at rest 12.86,on:15.76...these readings are at the battery and at the alternator.my guage inside won't go over twelve,but whatever .i hav ethe results under the hood.....and brighter headlights.:lol:

so, anyone with an ea82 w/ac does this swap yet? :D

My voltage reg went out last week, so I thought I would try this on my 91 Loyale - it has AC. Unfortunately, the new alternator unit had a lot less space between the ears than the one in the pictures. I would have had to cut away about 3/8" on each ear! Took it back and compared to some others at the parts store; they were all the same. I don't really need the addtional power, so I just bought an OEM alternator and finished the job.

 

Other than that problem, it looked like it should have fit in the space available, although it would be close.

  • 5 months later...

Bump. It doesn't look like this write-up made it to the USRM, and I wanted to give it a try.

  • Author

Yeah, it was there once before... did it get lost in the "adjustments" that were made to the USRM?

  • Author

Aaaahhh, I see that it is no longer there. Reason why? I dont know.

 

I also coulda swore that I included a link to the writeup within this thread. Oh well, here we are once again:

 

http://random.fjeer.us/altswap.html

 

The complete writeup is available at the above URL.

 

Cheers. :)

  • Author

Oh yes, and since its been about a year, heres an update on this swap.

 

I've since finished re-doing my bad rump roast headlight relays, and am now pushing 700 watts through my stock headlamp locations. Feel the heat! ;)

 

Well, after about a week of running with the new highs, and having to jump off several other vehicles, I finally toasted my stock harness, and I mean toasted it! Smoldering plastic was the result.

 

The solution was easy, and was mentioned earlier in the thread: run a heavy gauge wire from the alternator direct to the battery. I personally ran a 0 gauge from the alternator charging lug, to the hot side of the battery, cut off the fried end from the original harness and shrink wrapped the puppy. The battery meter on the dash continues to operate normally, it just gets its voltage reading from the other end of the harness now. ;)

 

As a safety thing, I also swapped out the old alt for a new one under warranty. I wasnt really fond of how the plastic isolator on the alternator also somehow got hot and melted. No biggie. Warranty swap, filed it down, and kept on truckin.

 

This concludes my update. Rock on.:headbang:

  • 2 months later...

well i realize its reviving an old thread.. but since no one else had commented on it, i HAD to put in my two bits......

 

 

theres gonna suddenly be ALOT of chevy guys who dont understand why their rebuilt alternator has that little bit of slop on the pivot bolt.... :banana::lol::eek::headbang::rolleyes:

theres gonna suddenly be ALOT of chevy guys who dont understand why their rebuilt alternator has that little bit of slop on the pivot bolt.... :banana::lol::eek::headbang::rolleyes:

 

YEAH. and wonder why there has been a HUGE increase in demand for them!:-p

  • 2 years later...

Hmm, well just saw this thread, The previous owner said he installed a GM alternator, says it 160 amps... IT is huge, Heres a picture, cause I love pics, after reading this im afraid something will burn out and catch on fire, hmmm

 

n846795391_5053300_8029.jpg

 

n846795391_5053299_7774.jpg

  • 2 months later...

I have an 81' Brat Gen 1 ea81 with an external regulator, would this swap work for me?

 

thanks,

Kurt

with an external regulator unfortunately not directly.

 

HOWEVER, I did a bit of wiring diagram study years ago when I wanted to convert my alternator on my gen 1 to internally regulated. Its actually as easy as cutting the connector off of your regulator and splicing 3 sets of wires together and plugging your spliced connector back into the harness.

 

Lemmie look around and see if I can find one of the connectors I modded.

So if I can my external voltage reg. And make the 3 connections on the pigtail, I can throw in that High amp GM alt?

 

-Kurt

HOLY CRAP!!! This is an old thread!

And an extremely useful one at that! :D

I'll be doing this swap asap, as I believe my alt is on the downhill :-\

All I run is headlights, fan, multimedia gps, and 200w stereo.

And my voltage slowly sinks down, till I kill the fan and gps.

Then it takes about 10-15 minutes to get back up to 12-13 volts. :-\

So, maybe I'll be able to run my fogs, and my overheads,

without killing my battery. :headbang:

 

Twitch

I went to autozone today and brought my alt from a gen 1 brat and it looked like there is far more than 1/16th of an inch to shave off, closer to 3/8 so I didn't pick it up. Is the bracket from a 2nd gen different than one from a first gen?

 

thanks,

Kurt

I went to autozone today and brought my alt from a gen 1 brat and it looked like there is far more than 1/16th of an inch to shave off, closer to 3/8 so I didn't pick it up.

 

I got my Duralast 7157 from Autozone as well, but I did grind off the 3/8 on each ear (much to my shagrin) and had to put a spacer on the pulley. Next time I swap it I will mod. the alternator bracket instead.

 

It seems like the older 7157's I have seen in the JY are larger cased. Mine is 4 inches thick exactly.

 

I was hoping other people that have done this swap could pull a measurement off theirs along with brand and place of purchase, so we could figure out where the thicker ones can be found.

 

Duralast 7157

Autozone

4 inches thick

 

CIMG2592.jpg

  • 5 months later...

Yay! Just finished the alternator swap in my 81 GL Brat. I used a different alternator sourced from an old Astro van at Pick n Pull. It's a 100 amp Duralast with a lifetime warranty. I'll hafta find the part number, but mine was a little more tricky than the ones already discussed, but it's even smaller than the stock alt.

 

The headlights haven't got any brighter, but they no longer pulse with the engine. It probably helps that I have them relayed straight off the battery.

 

I had to swap the pulley and trim down the spacer from my old alternator. Then I used a 10 mm bolt through the factory swivel point. Had to grind that hole a touch bigger with a Dremel to fit the bolt through. Then since this alt is too small to reach the curved slot in the bracket, I cut a piece of 14" x 1' steel strap to go from the adjusting hole to the curved slot.

 

The suck part is that the new alt was mounted on the right side of the engine. So I had to grind notches in it to clear the alternator and allow the strap to take a very extreme angle. Had the new alt been a left side alt, the strap would have been much easier.

 

Now I finally have the juice I need to install the stereo amplifiers and speakers I want.

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