91 jimmy power mirror problem

i have a 1991 GMC Jimmy SLX 4x4 4dr. w/ p/w, p/l, "p/mirrors", digital dash.... and much much more.. but if i try to move the mirrors it make a chattering sound and pops the fuse right away... it runs on the "HORN" fuse... but i have looked threw the wiring some and i never seen any "corosion" and felt no "lose conections"... but still nothing... i can freely move the mirrors by hand so the motors are stuck... but its got me beat... in the Haynes manuals (both books #24070 and #831 cover these trucks) they say nothing about power mirrors and its not even in the wirring diagrams... so.... any got anything that might help a little... it would be muchly apreciated... if i tap that switch "pop" no horn, no interior lights...

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1991 GMC Jimmy SLX Loaded w/o leather (Daily Driver)
1987 GMC Jimmy SE w/ nothing but mud (PARKED)
1989 Chevrolet Corrsica LT Loaded w/o leather (FOR SALE)
2005 Pontiac GrandAm Loaded w/o leather (GIRLS CAR)

if it is popping the fuse their has to be a short of some kind some where, might be the switch is grounding out on something but if it pops only when you hit the switch i would take an educated guess that your short is between your mirror and your switch.

i am goin to test the switch today... and if i can get some more spare time this weekend i will test the whole wiring system for continuity... loads of fun

switch tested fine.... so its got to be somewhere in the wires... if anyone knows where i can get a good diagram... or any diagram for power mirrors it would be muchly apreciated....

The wire continuity issue should be between the switch and the mirror, not alot of wire to deal with, it should just run up in the door for the driver side, of course then you have the passenger side... not fun, check the color scheme of the other wire and try to trace it.