A/C blows the Blower Fuse.

I went out to test the A/C system today, and whenever I turn it on it runs for about 5-10 seconds but the voltage gauge drops to 12V, then the Blower fuse blows. Anybody have any idea what could cause this?

What year? When on heat, does the blower blow on all speeds without blowing the fuse? Then you put is on AC and it blows the fuse? What does the voltage gage read before you turn on the AC? Do the RPM's drop down when you engage the AC? Compressor drag could bring down voltage which causes more amps to flow over fuse. Watts (power drawn) = volts x amps. Lower volts draws higher amps to do work. Try unplugging the compressor to see what happens. Doing all this is also putting your blower speed resistor at risk, so leave the blower on high speed to take that out of the equation.

It's a 1989 (Renix). The heat works on all speeds, but blows on any A/C setting. Voltage is 14V before I turn the A/C on. It does not blow the fuse when on A/C with the engine off (but key in run position).

I'll try unplugging the A/C compressor.

With the compressor unplugged it still blows the fuse.

Try adding an extra ground wire from the blower motor negative terminal to the body. Scrape away any paint or other junk at both connection points. A poor ground increase resistance in a circuit.

It's probably a combination of a worn out motor, which has toasted your switch due to faulty chrysler wiring:

http://www.jeepforum.com/forum/showthread.php?t=580627

Wait a minute! This is the easy standard old answer for the blower motor circuit. To me, the big question is why the fuse blows on AC and not on heater??????????

What happens with the voltage when the fan is put on in AC and in heat? Is this all with the blower only on high, or at all levels.

winterbeater said:

Wait a minute! This is the easy standard old answer for the blower motor circuit. To me, the big question is why the fuse blows on AC and not on heater??????????

What happens with the voltage when the fan is put on in AC and in heat? Is this all with the blower only on high, or at all levels.

Click to expand...

Dunno, but mine did exactly the same thing.