Go Back   Mitsubishi Forum - Mitsubishi Enthusiast Forums > Mitsubishi Models > Mitsubishi Lancer and Lancer Sportback
Sign in using an external account
Register Forgot Password?
Search

Welcome to the Mitsubishi Forum - Mitsubishi Enthusiast Forums.
If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Reply
 
 
 
 
LinkBack Thread Tools Search this Thread
  #1  
Old 07-25-2011, 07:59 PM
Junior Member
 
Join Date: Jul 2011
Posts: 3
Default A/C Low Pressure Switch

04 Lancer Sportback LS - Is there a (secondary) low pressure switch inside the compressor preventing the clutch from engaging? If so, can it be jumped and how?

It's probably time for a compressor but would love reassurance. I just purchased an 04 Lancer Sportback LS knowing it was blowing warm air. Per the salesman a schrader valve was recently replaced but a turn of the dust cap confirmed it was still stuck open. Figured it was a cheap & easy fix. I don't recall the compressor cycling before evacuating but wish now I had paid more attention.

After evacuating the system it will not take any freon because the clutch will not engage. The compressor is getting voltage when the A/C dash switch is on but none when it is off. The same is true with the fan. There is a switch along the right fender on the high pressure line. I have to assume this is the low (and high) pressure switch. Disconnecting this switch kills power to the compressor and the fan. Static pressure is 20 lbs on both sides so I assume the orifice is OK. I switched around a few relays to confirm and the fuse is fine.

A new compressor then? Am I missing anything else obvious like a fuse on the compressor or a reset switch? Thanks for the help.

Chris
95 Montero SR (replaced the ac compressor 10 years ago and still cold)
04 Lancer Sportback
10 Outlander LS 4WD
This ad is not displayed to registered members.
Register your free account today and become a member on MitsubishiForum!
Reply With Quote
  #2  
Old 08-01-2011, 02:42 PM
Junior Member
 
Join Date: Aug 2011
Posts: 4
Default

20lbs on the high side is too low.

if there isnt enough pressure the compressor will not turn on.

so my next question is how are you testing for voltage at the compressor? becasue if there is not enough pressure in the line the pressure sensor will not allow the compressor to turn on.

is the compressor block grounded or not? if not check the ground for power, as some pressure sensors actually control the - not the hot side
Reply With Quote
  #3  
Old 08-08-2011, 09:07 PM
Junior Member
 
Join Date: Jul 2011
Posts: 3
Default

Thanks for the response. I was checking voltage at the single (hot) lead into the compressor. I wasn't able to safely check it at the clutch pulley. In hindsight I should have checked resistance from the compressor block to the engine block since there is no (-) wire out. It a great tip for future diagnosing.

I was puzzled about the low pressure and why the compressor would not turn on. I could not get the pressure any higher, though, so I had to assume something electrical was going on (or not going "on") inside the compressor.

Desperate for a/c and for lack of being able to get more than 20 lbs into the system I chanced a $140 junkyard compressor. After swapping, it charged perfectly and blows super cold. I'm still curious if the compressor has an internal pressure sensor but I'm pretty sure now that it was just the clutch. Maybe a bench test will confirm.

Lesson learned: Never assume the obvious problem is the ONLY or most serious problem. So take lots of measurements BEFORE starting, even if doesn't seem relevant to the repair.

Thanks again.
Reply With Quote
Old 08-08-2011, 09:07 PM
 
 
 
Reply

Tags
03, ac, clicking, compressor, engage, high, lancer, low, mitsibishi, mitsubishi, pressure, sensor, side, switch, wont


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Advertising

Featured Sponsors
Vendor Directory
Our Sponsors
All times are GMT -5. The time now is 08:23 AM.

Internet Brands, Inc.



SEO by vBSEO ©2010, Crawlability, Inc.