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Author Topic: Delco 21SI 200amp Alternator Short Lifespan!  (Read 3864 times)

bigblockwagon

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Delco 21SI 200amp Alternator Short Lifespan!
« on: July 12, 2012, 12:42:47 AM »
I replaced my old Leece Neville (dead) with a Delco 21SI 200amp alternator on my 1991 Monaco coach powered by a C6TA8.3 Cummings. The self exciting 1 wire alt worked out very well and charged great for 1/2 dozen trips then the tach started jumping around and finally it stopped charging completely. I don't know the exact size of cabling but it is very large with short runs between the alt, isolator, battery's ect. I was told that the 21SI would not handle the heat being a diesel pusher w/side radiator.

What would fail after such a short lifespan? Internal regulator? Bridge Rectifier? or ?? Right now I need a quick fix for an rapidly approaching weekend trip but I would also like to know the best options to get maximum lifespan out of it!
Thanks, Ken

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Delco 21SI 200amp Alternator Short Lifespan!
« on: July 12, 2012, 12:42:47 AM »

drew

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Re: Delco 21SI 200amp Alternator Short Lifespan!
« Reply #1 on: February 20, 2013, 03:54:16 PM »
It sounds like heat caused your bridge rectifier to fail, and then your voltage regulator soon after. We are currently developing a blower motor specifically for use on diesel pushers with side radiators.