Electrical problem
1991 GMC C2500 V8 Two Wheel Drive Automatic 200000 miles

i am having a wiring problem- i have heard about the early 90's trucks gauge panels going out- i was driving and looked down and saw that all my gauges had went nuts-all exp. speed. so i was going to try to make it on to the house but then noticed headlights getting dim-hmm pulled into autozone with enigne running and checked alt. no good-so replaced it- jumped it off and went to leave but headlights still dim so pulled back in walked inside to borrow voltmeter- i checked the wiring going to the alt. guess what- the "igintion hot" was dead- so i cut and run a temp. wire over to batt to check- started it back up and guess what- full 14.7 volts! put old alt. back on with the temp. wire run to batt. to make it home. well here is the problem -i replaced the "faulty gauge panel" andstill i am poping fuse- 20 amp as recom. checked everything i could think of - unplugging 1 at a time to check for shorts- computer, then plugs going to steering column, most sensors - temp. oil,then moved on down the line, well i am stuck---- what a headache- i have started to remove entire dash to look for a short or maybe a rubbed though wire or somthing- this is driving me nuts! all lights work- just no power to alt. from firewalll, and fuse for gauges keeps poping -HELP