Compressor does not cycle

Friendly format provided to inquire about automotive a/c systems.
Archived Forum

Moderators: bohica2xo, Tim, JohnHere

Post Reply
canadmin
Posts: 6
Read the full article
Joined: Tue Jun 23, 2020 6:08 pm
Location: Vancouver Island BC

Compressor does not cycle

Post by canadmin »

I am working on my neighbours 2014 Ram 1500 with 5.7 gas engine. The ac hasn't worked since he bought the truck a couple of years ago. I have replaced the compressor, expansion valve and dessicant bag. The ac is working very well now providing a lot of very cool air. High side pressure is about 225 and the low side about 35. However, the compressor is always running. It does not cycle off and on. Through my research, I've found opinions ranging from "don't worry about it" to "replace the ambient temp sensor and the interior temp sensor". I found the ambient temp sensor but have not been able to find the interior sensor. My question is, do I leave it as is or do I need to replace the sensors and where is the interior sensor? Thank you.
tbirdtbird
Preferred Member
Posts: 1448
Joined: Sat May 02, 2020 1:48 pm
Location: Texas

Re: Compressor does not cycle

Post by tbirdtbird »

Ambient?
When considering your next auto A/C purchase, please consider the site that supports you: www.ACKits.com
User avatar
JohnHere
Preferred Member
Posts: 1555
Joined: Sun May 13, 2018 10:20 am
Location: South Carolina Upstate - USA

Re: Compressor does not cycle

Post by JohnHere »

A 35 PSI reading on the low side indicates an evaporator temperature of around 40 degrees. Was 35 recorded at idle? What are the low side and center vent temps at 1,800 RPM?
Member – MACS (Mobile Air Climate Systems Association)

Thankful for the responses you have received? Please consider making a monetary donation to this Forum.
DetroitAC
Preferred Member
Posts: 269
Joined: Mon Oct 17, 2016 10:33 am
Location: SE Michigan

Re: Compressor does not cycle

Post by DetroitAC »

It's a variable displacement compressor, sounds like it's working properly. The clutch will not disengage as long as the climate control head is on and in a mode that calls for compressor on, or as long as the ambient is above freezing plus a little bit.
canadmin
Posts: 6
Joined: Tue Jun 23, 2020 6:08 pm
Location: Vancouver Island BC

Re: Compressor does not cycle

Post by canadmin »

Thank you DetroitAC for not replying with more questions. Your explanation makes perfect sense to me because everything is working perfectly other than the compressor cycling and now I know that the system is indeed perfect. Thanks again.
tbirdtbird
Preferred Member
Posts: 1448
Joined: Sat May 02, 2020 1:48 pm
Location: Texas

Re: Compressor does not cycle

Post by tbirdtbird »

???
When considering your next auto A/C purchase, please consider the site that supports you: www.ACKits.com
Post Reply