Audio Systems: Fuse blows out as soon as replaced, gas gauge, temperature readout

Question
I have a Cadillac 1988 Sedan de Ville. My son connected a stereo for me and as soon as it was connected, my digital gas gauge readout and temperature readout as well as the fan, heater, air conditioner, etc. stopped working.
I tried replacing the fuse which was burned out and everytime I put a new one it it immediately burns out. My son tried to find out where the wiring was wrong, but had no luck. Would you be able to tell me which color wire could be the one that would be causing this problem? Thank you.  

Answer
Cherie,

 ok now i hope your son used a wire harness adapter plug, instead of cutting the factory plug off and wiring the wires directly to the new unit ? if he did this .. that is where your problem is you should never cut the factory harness unless there is no other way you can work with it, what you needed was a wire harness adapter about 10 bucks from radio shack this wires in color for color on your new units harness then simply plugs into your factory connector so everything is neat and correct, ok enough of the letcure lets get you going , look at www.streedreams.com/wires they should have a color code for your wiring, you or your son go over all of the wiring to make sure everything is correct and no crosses... i hope this helps you out if you need anything else let me know

thanks