'90 Mustang LX 5.0-No Turn Signals, No A/C or Heat Fan

About two weeks ago my turn signals quit. I changed out the flasher, but that didn't solve the problem. Well yesterday I went to use the A/C and though the compressor kicked in there was no airflow - the fan wasn't working. I checked a few fuses, but couldn;t find any that were blown. I did notice that the fuse for the fan seemed to have overheated from teh outside because the plastic part of it was slightly melted on one side. Are the two events related? Any ideas?

Electrics, are strange.

I would not think they are related, but you never know.

Sounds like your fan is shorted. Take it out, and check it.

If your blower will not come on, try hitting your dash, this may kick the fan on.

Time to get out the test light, ohm meter, and a wiring diagram. If the fuse is melted, then the wiring is over heating, usually caused by a short. Is the fuse really good? Did you test it to see if power is going through it? Is there power going to the fan when the switch is on? Is there power getting to the turn signal switch? Was the flasher bad, or were you guessing when you replaced it?
I have made enlarged copies of the wiring diagrams for my cars. This makes them easier to read and trace circuits. To diagnos electrical problems, you must be methodical. Follow the circuit, test each component until you find the fault.
Years ago my friends toyota had multiple electrical accessories fail. I looked at the wiring diagram to find a common point for all these failures assuming all the failures were connected. It took about fifteen minutes to trace all the circuits to a common point, and another ten minutes to inspect the part. Her fuse panel had burned up and was only noticeable after unbolting it from the car and looking at the back of it (I didn't unplug anything on the fuse panel, just disconnected the battery when I looked at it). What caused the panel to burn up? After replacing the panel, I turned things on one at time until I found the cause. The wiring to the power mirrors was shorting between the switch that controls the mirrors and the motors that move the mirrors.

Thanks for the feedback and advice. I think I found the problem. It seems that the ignition had failed. I doscovered this while I was inspecting the wiring and the fuse box. I had removed the plastic cover from around the steering column so that I dcould remove the lower portion of the instrument panel cover and inspect the wiring. After fiddling with the fuses I wanted to try the turn signals so I switched on the ignition. When I did this, half of the ignition fell to the floor, along with a spring and a ball bearing. I picked up the pieces and put them all back together and voila, the turn signals and blower worked.

After a quick trip to NAPA I had a new ignition. So far the lights and the blower are working fine.

Thanks be to God!

Great to hear you found the prob.