Alternator

[Minkota]

So after looking at the mounting bracket that is on the truck I am not sure a CS will fit. is the Bolt pattern / spacing the same for the SI as what I currently have installed?

[MARKDTN]

Looks like you have a long water pump and later accessories with aftermarket upper alternator bracket? You may have to modify the upper bracket, but the bottom would bolt right in. When I did mine (in an '83, so RH side) I used mid-80s style crank and water pump pulleys that had a serpentine style for just the alternator, it has v-belts for a/c and p/s.

[Minkota]

Originally Posted by MARKDTN

Looks like you have a long water pump and later accessories with aftermarket upper alternator bracket?

This was all on the truck when I purchased it. Does the 10SI or 12SI have the same bolt pattern as the 10DN that I currently have installed. or will they require modifications as well?

[MARKDTN]

Originally Posted by Minkota

This was all on the truck when I purchased it. Does the 10SI or 12SI have the same bolt pattern as the 10DN that I currently have installed. or will they require modifications as well?

10si, 12si, and 10dn are all dimensionally the same as far as mounting.

[Minkota]

Originally Posted by MARKDTN

10si, 12si, and 10dn are all dimensionally the same as far as mounting.

well I had a brand new in the box 12SI that has been sitting in my garage since 2000. I was going to install it, decided to go down to local parts store and get it tested, it failed. i will be purchasing a new one this evening.

thanks everyone for all the help on this issue.

[Minkota]

So I installed the 12SI and it charges fine while driving 14.7v) but at idle it’s only at 13. Is this normal?

[Steeveedee]

Minimum should be 13.5V. Did you have any accessories running? It may well be that it is 13.5V at the battery, though. Don't condemn it, just yet. Measure it at the battery with a meter just to be sure.