Fan problems (no low speeds, slows down when accelerating)

Hi guys. Having a slight odd occurrence with my 96 XJ with the 4.0l and AC.

When driving, no matter what setting the HVAC system is on, whether it be on AC or just vent, when the gas pedal is pushed probably anywhere near 50% the interior blower doesn't blow as hard. Didn't notice this with my 99 XJ so I'm figuring there may be a simple fix for this.

Also, the fan switch itself only works in the high position, any of the lower settings seem to push out very little to absolutely no air.

Any ideas?

It may be a vacuum leak. The HVAC controls are run on vacuum. When you run out of vacuum due to engine load and a vacuum leak, the vents go stupid and you get reduced or no air flow.

Make sure your vacuum bottle is connected and you are getting good vacuum.

Ron

Only working on high usually means the blower motor resistor is fried, or one of the connectors between there and the back of the fan speed switch is burnt.

two things to check

thanks guys!

X2 - resistor blown and vacuum leak