AC low pressure switch 95 Georgie boy 454

[okie mopar]

How do I test the 4 wire low pressure switch on a 95 454? Where would the fuse are relay be for this ? I can't make out on the wiring diagram which is which. Thanks for any info. on this.

[BFlinn181]

Most likely the relay would be in with the other chassis fuses and relays, often a box in engine compartment or perhaps under the dash board, according to where the RV builder arranged the wiring loom.

The low pressure switch generally just passed 12 v through if the pressure is proper, yours might also be used to control other items, like the fans on condenser coil and the like. If pressure is too low, the switch would have 12 v on one wire and none on one or more of the others.

[okie mopar]

How do I keep the comp running so I can add Freon if it is low?

[twinboat]

I always jumped the low pressure switch with a cotter pin, while connected.

[BFlinn181]

Problem is that if the refrigerant is low enough to trigger the low pressure cut off switch, you've got more than a slight leak. Just adding refrigerant won't cure that, I'd have it repaired, evacuated, then refilled.

[Deep Water D]

Warm up the refrigerant and feed the gas into the low side. Eventually you'll get enough pressure in the system to keep the switch closed. I usually use a pan of very warm water to keep the gas flowing. Compressor will cycle a few times until you get enough refrigerant in. You sure it's low on gas and not just a bad switch?