Hi, new to the forum. I have a Mahindra 3540 Shuttle Shift and recently the alternator gave up the ghost. The dealer wanted $800.00 for a new one so I put a GM 10SI 3 wire 105-amp alternator on it. As soon as the engine starts, it blows the 40-amp main fuse. Do I need to replace the 40-amp fuse with a 60 amp maybe because of the higher amp output or possibly put a resistor in line? Anyone with experience doing a swap to a higher output alternator? Thanks
Alternator replace with 10SI GM
- Thread starter RandyH79
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Roadworthy
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Are you using the original voltage regulator or did you get a GM regulator as well? The original regulator may not be able to handle the new alternator.
Tinhack
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The 10SI has a built-in regulator. That's what the SI or "System Intergrated" means. You have to wire it so as to Bypass the original voltage regulator. I hope you didn't smoke the Alternator. Its output is already DC and regulated. Below is one way to wire the alternator (there are several). It makes use of a charge/discharge light.
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I would have went with a single wire alternator myself.
Tinhack
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So, when you're sitting out in the middle of a field with a dead battery because the alternator belt broke, you wonder why you didn't wire in the idiot light. 
The "3-wire" SI can be wired without the light or as a "single wire" as well. The discharge Light comes in handy though.
The "3-wire" SI can be wired without the light or as a "single wire" as well. The discharge Light comes in handy though.
Thanks for the replies and info y'all. Got it working. I made an adapter out of a blown fuse and hooked it to a 120 amp breaker. Everything works as should now no problems. I have ordered some 100 amp fuses to try and if it works, I'll use it instead of the 120 amp breaker. I'll let you know but it's working great now. Had to modify the existing mounting hardware and put the old pully on the new alternator using a spacer to keep the fan from rubbing against the housing. I'll try to post some pics tomorrow.
The 10SI has an internal one. Got it going . thanks