A/c Problem

[bobinvt]

I'm having an A/C problem on my 2000 Suburban with computer controlled A/C. This has happened a couple of time in the past year and has cleared itself up before I could really investigate. This time it seems to be here to stay. The front blows air just a few degrees cooler than ambient while the rear is working normally (blows 40 degree air).

 

My investigation has revealed the following:

 

Compressor is running

System low side pressure is within specs

Line going into evaporator (through firewall) is cold

Line coming out of evaporator is slightly warm

Evaporator core (as felt through cabin air filter access) is not even cool

Blend and mode doors appear to be working properly

HVAC module shows no codes

 

Any ideas?

[bobinvt]

An update:

 

Saturday it was working OK, not super cold but in the low 50's. Yesterday afternoon we went out for a bite to eat. On the way it was OK, on the way back not so much.

 

Should the accumulator get cold? My S-10 does, the Suburban does not.

 

I'm thinking maybe there is dirt or something restricting flow through the orifice or evaporator. It moves around and sometimes allows enough flow and sometimes not.

 

Anybody else have any ideas?

[apd123]

Ok check this first its an easy fix if this is the prob have you checked to see if you resistor is working? Its located in the fan box on the passenger side and this sometimes presents a problem like this. On the question about the accumulator getting cold mine does on all of my vehicles.

 

Try changing your accumulator and when you do this take all your lines off and spray some cleaner through them this might help. I would prob try the orfice and cleaner first and if this doesnt work I would try the resistor next.