AC Compressor Switch?

[jstaples2]

Hi all -
It's been a while, but I'm back. I've got a question about the receiver/drier. I sprung a leak over the summer in the receiver/dryer and all my refrigerant went out... I'm looking to replace the receiver/drier and found one at O'reilly's - however when I go down to pick up the part it has this switch on it... totally different from the pictures ob the site.

My old one doesn't have this switch and now I"m trying to figure out if this one will work or not. What does this switch do? If it's not plugged in does it keep the refrigerant from flowing?

 

[commando1]

You can remove it and put in a NPT plug.

 

[Davea Lux]

The switch is a Hi-Lo pressure unit. It is a safety item which keeps the compressor from running with gas pressure that is too high or too low. Most Mopar systems have this switch on the filter dryer. Some also have this switch on the high pressure line, In any case you can leave this switch on the dryer unplugged if you system does not require it because you have this switch elsewhere on the system. It will not block the refrigerant line. Take care in removing the old filter dryer as the fittings sometimes get fused to the refrigerant lines and can cause them to twist off. The system should be evacuated and recharged with oil prior to adding fresh refrigerant. Your old filter dryer will probably have a plug in the side of it than can be removed to replace switch on the new dryer if you choose to go that route.

Dave

 

[65sporty]

Dave beat me to it, leave it or plug it like commando said, wont make a difference in the operation because your system has other switchs

 

[Ross Wooldridge]

It's a pressure sensor for systems that have a cutoff switch built in to protect the system in case of loss of Freon.

 

[CBODY67]

I know that our '72 Chrysler had that switch, but the '66 did not. Don't remember the exact model year they started using that switch. Even if you could have purchased a new item from Chrysler, at this time, it would have probably been superceded upward to the "switch" unit.

It's good that the new receiver/drier has the switch on it, all things considered, even if you don't need it for your particular application. I suspect the replacement receiver/drier is probably a little different physical size, too?

Make sure the replacement item has a bit of system oil in it prior to installation, for good measure. Oil always seeks the lowest level to "drain" to, internally, which is why the systems need to be operated in the cooler times of the year to keep the oil "moved around". Later systems run the compressor when the defroster is activated, probably for that reason or to help dehumidify the output air.

CBODY67

 

[jstaples2]

Thanks guys. I'll hook up the new unit and take it to Firestone to flush/oil/charge the system. One more question... the receiver/drier unit has a side marked 'IN' - I didn't pay enough attention to how the old one was oriented - does the 'IN' side go the side closest to the condensor?

 

[Clover]

Yes.