I have a 95 Ford Explorer that has a bad a/c pressure switch. it is the switch that is attached to the compressor on the backside and if I jumper out the wires the a/c works great. i recently bought a new switch, but my question was if i needed to evacuate the r-134a before replacing? Can anyone help me out with this?

 

Moved to correct forum.

No, it has a shrader valve under the switch.

 

Why do you suspect the switch is bad versus having an incorrect charge of refrigerant?

-Rod