MR2 Alternator Upgrade?

General discussion about our beloved Tercel 4WD cars
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4wdEconoBox
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MR2 Alternator Upgrade?

Post by 4wdEconoBox »

I know its been discussed here a few times but I couldn't find any definitive info, would an alternator from a 1991 MR2 N/A fit our cars?? Everything looks the same. Anddd, they come in 70, 80 and 100 amp, looks very promising, I'm talking to someone about getting a used one for hopefully cheap!
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4wdEconoBox
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Re: MR2 Alternator Upgrade?

Post by 4wdEconoBox »

Looks like the pulleys may be the only difference? MR2 looks like is uses a 4 rib belt, and ours is a 3 rib isn't it?
Notmikeb
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Re: MR2 Alternator Upgrade?

Post by Notmikeb »

The adjuster ear is at 1 o'clock instead of 12 but other than that it seems like it will work. May have to slightly re-arc the tension arm.
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4wdEconoBox
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Re: MR2 Alternator Upgrade?

Post by 4wdEconoBox »

Good eye! Still looks like it would be the easiest upgrade. Hopefully I'm able to get that used alt so I can try some test fitting!
Notmikeb
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Re: MR2 Alternator Upgrade?

Post by Notmikeb »

I used a 70amp one from a 22re pickup truck and had the same issue (mine was clocked at 11). Removed the bracket and heated it with a MAP torch in a vise. Big 2lb hammer and everything lines up perfect now.
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1985 Tercel 5dr Hatchback
2003 Chevy Suburban
2014 Ford Flex

"I don't get it! I've cut this thing FIVE times now and it's STILL too SHORT!"
teranfirbt
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Re: MR2 Alternator Upgrade?

Post by teranfirbt »

Depending on clearance to the block, a shorter belt + modding the top bracket would probably do the trick. The number of ribs in the belt isn't super important unless you're going from 60 amps to 250 amp. I'm running a 6 rib pulley 105 amp GM alternator with a 4 rib belt.
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4wdEconoBox
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Re: MR2 Alternator Upgrade?

Post by 4wdEconoBox »

Alright, thanks for the helpful info y'all!! I'll know more about what route to take once I get one! Hopefully it won't be too long, I have a feeling that the bearings in mine are about to go out...haha
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Re: MR2 Alternator Upgrade?

Post by Petros »

there are two differnt electrical connectors used on the Tercel alternator, that one looks like the earilier one as I recall (though I am not certain about that). It should not be a problem to swap that out if you change it, I went to the later style alternator and made a pig tail adapter if or some reason I want to switch back to the earlier style alternator, I can unplug the adapter and plug the original connector into the back of the alternator. I only did it because my '84 alternator finally gave up the ghost after about 300k miles (and 29 years), and I happen to have the later style one in a box of parts in my garage, so I swapped out the mount and made the adapter for the connector.
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4wdEconoBox
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Re: MR2 Alternator Upgrade?

Post by 4wdEconoBox »

What did that 105 amp GM alt come off of teranfirbt? How hard was it to fit it on our car?

And does anyone mind snapping a quick picture of their modded alt bracket, just so I can see where yall bent it at? I'm guessing yall are talking about bending it where it bolts to the block?

And from what I can tell its the same connector as mine, unless the difference is in the diameter and not the pin out. But either way, like you said petros, it shouldn't be terribly hard to make a piggy tail adapter just as a precaution.
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Petros
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Re: MR2 Alternator Upgrade?

Post by Petros »

if your connector fits, it will have the correct pin-out. the two styles are the round connector, like on that alternator, and the other is more rectangular, but kind of offset. they are not interchangeable, so no worries, if they fit you are good.
'87 Tercel 4wd SR5 (current engine swap project)
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Re: MR2 Alternator Upgrade?

Post by xirdneh »

i have used alternate alternators but usually have a problem with adjustment tang being set back too far or too far forward. have modified the upper hanger that mounts to head to suit (cut and weld)
Love those Tercell 4x4 wagons but they sure suffer from road noise.
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Re: MR2 Alternator Upgrade?

Post by teranfirbt »

4wdEconoBox wrote:What did that 105 amp GM alt come off of teranfirbt? How hard was it to fit it on our car?
I pulled it off a GM B-Body with a V8 (95 Caprice works). It was part of my 5A swap, but could be done fairly easily on the 3AC:
Image
The wide mounting lug on the bottom is narrower than the Tercel alternator, so I put a stack of washers in to tighten it up. Top lug is further away than the Tercel alt, would take a little custom work to make the top arc line up. Wiring is pretty simple, switched 12V to the "F" pin and direct battery 12V to the "S" pin (letters are molded into the connector on the alternator).
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4wdEconoBox
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Re: MR2 Alternator Upgrade?

Post by 4wdEconoBox »

Alright, heck yeah, that looks like it would be another good alternative! Plus I bet you could find one of those alts much easier if/when you needed one!
teranfirbt
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Re: MR2 Alternator Upgrade?

Post by teranfirbt »

Yep, plus they were used on every GM 5.7 from the mid 80's to the mid 90's, so are stupid cheap for remans, and 100 bucks brand new.
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4wdEconoBox
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Re: MR2 Alternator Upgrade?

Post by 4wdEconoBox »

Hmmm, that alt is looking more and more appealing then! haha
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