Moparts

A/C vacuum switch replacement?

Posted By: 70runner

A/C vacuum switch replacement? - 08/17/17 05:02 AM

Restoring 69 Charger a/c system. Replaced inop vacuum switch with NOS 3502126B which was advertised as supersede for 68-70B/C bodies. Switch seems to work ok except it energizes the a/c clutch on defrost mode. 69 Serv Manual says no a/c clutch on defrost. Anyone know whats going on here?
Posted By: RapidRobert

Re: A/C vacuum switch replacement? - 08/17/17 06:15 AM

I'm wondering if the A/C clutch gets engaged on defrost on 68-70 B/C bodies. If "no" that would make me think there is a problem elsewhere. Here's a BTT for ya.
Posted By: 70runner

Re: A/C vacuum switch replacement? - 08/17/17 06:40 AM

According to the 69 serv manual, compressor (a/c clutch) is off during defrost. Read somewhere that later switch supersedes may energize clutch for defrost. Don't know how the part numbers (there are several) map to this...
Posted By: Supercuda

Re: A/C vacuum switch replacement? - 08/18/17 02:05 AM

If having the AC on for defrost bothers you, then push the button in and pull it back out to deenergize the AC.
Posted By: Siba

Re: A/C vacuum switch replacement? - 08/18/17 04:31 AM

It's a good thing to have it engage, just like a modern car does it. Removes moisture when the compressor runs.
© 2024 Moparts Forums