Alternator question

shawn deere

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hey guys, got an alternator from summit and they want my feedback. Im not real happy. Called em up and gave them a shot though.
Got a powermaster from them, had to swap pullies with the old alternator due to the vacuum pump belt (new alternator had a smaller single groove)

The product guide says the powermaster will work on an '89 mine is a '90.

Does the '89 f350 7.3idi have the same pully setup?

I have to rev 2k to get this thing to start working (partly because the old pully is bigger and turns the alternator slower, but i needed the 2nd belt for vacuum pump....)

Thanks!
 

IDIoit

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there has been a few threads on this lately.
ive taken apart a lot of v-belt systems from various years.
they all seem to be the same.

im going to take a guess that the pulley set up the pulley is for could be for a gasser.
cant remember if my 89 460 truck had a v-belt or serp tho.

this whole issue can be eliminated with a serp system swap.

is this a 3g 1 wire?
 

franklin2

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Is that one of those 1 wire wonders? If so, that's what it takes to get them to charge. You can't let the alternator sit there with the engine off and be ready to charge, it runs the battery down. The factory used a signal wire from the cluster and the keyswitch to trigger the factory alternator to charge. Since these 1 wire alternators don't use this signal wire, they have to be creative and figure out a way to bring the alternator online to charge. Some of them use rpms, some of them use voltage drop from the starter motor through the battery.
 

shawn deere

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Is that one of those 1 wire wonders? If so, that's what it takes to get them to charge. You can't let the alternator sit there with the engine off and be ready to charge, it runs the battery down. The factory used a signal wire from the cluster and the keyswitch to trigger the factory alternator to charge. Since these 1 wire alternators don't use this signal wire, they have to be creative and figure out a way to bring the alternator online to charge. Some of them use rpms, some of them use voltage drop from the starter motor through the battery.
I can understand that. 2k rpm is excessive in my opinion, then summit said it was for a gas only when i called em. But it lists 7.3 international in the compatibility pages.
Just eas wanting to conferm that an '89 and '90 v belt setup was the same.

Thanks!
 

shawn deere

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It is indeed a one wire wonder. Should have done some homework, got in a hurry....
 

shawn deere

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I love mine.
internally regulated FTW
Thats what i thought!! Smaller two groove pully would help a bunch for me tho...

Opted for an 150 amp powermaster. I have a 12volt dc air compressor pump laying on a shop bench. The sucker pulls 90 amps. Thought i would upgrade to a super wookie alternator so i can run that bad boy when i get enough time to install it...
 

laserjock

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My 3G alternator was for a 427 truck motor. It had the double V belt pulls on it and charges at idle just dandy. It seems smaller than the original but I don't have a measurement. Might try running down one of those pulleys.

Actually here is a side by side.

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franklin2

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Thats what i thought!! Smaller two groove pully would help a bunch for me tho...

Opted for an 150 amp powermaster. I have a 12volt dc air compressor pump laying on a shop bench. The sucker pulls 90 amps. Thought i would upgrade to a super wookie alternator so i can run that bad boy when i get enough time to install it...

Just be warned, if you run the factory single belt on it, it will have problems driving the alternator much over 100 amps before it starts slipping. They don't tell you that either do they? You will notice the other guy in this thread with the 3g has a dual v-belt pulley. Or a wide serpentine belt will drive them also.

The stock 1G alternator was 100 amps.
 
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