Air Conditioner problems

[ScottLewis]

The other day, the passenger side vent on my dual zone A/C began blowing very hot air while the driver's side remained cold.. In June I had the compressor, condenser and other parts replaced because both vents were blowing warm but not hot like now. It worked fine until this week.

Could the slide temp control be the issue?
I'm afraid one or more blend doors may be the problem but don't know where to start looking.

 

[p-Bar]

The freon is low. the passenger side gets either the upper or lower part of the coil. Mine is doing it after 15 years time for charge.

 

[ScottLewis]

p-Bar- I would have thought so too. That was happening occasionally before the compressor, et.al, was replaced. Now the air coming from the vent is scalding, suggesting it's coming right off the heater core.

 

[p-Bar]

wow maybe a vent flap problem?

 

[cwbyinjeep]

The other day, the passenger side vent on my dual zone A/C began blowing very hot air while the driver's side remained cold.. In June I had the compressor, condenser and other parts replaced because both vents were blowing warm but not hot like now. It worked fine until this week.

Could the slide temp control be the issue?
I'm afraid one or more blend doors may be the problem but don't know where to start looking.

What year truck? 2003-2007 had horrible factory damper flaps that are prone to cracking apart, amazingly cheap plastic. I just did the full dash removal, new Evap and all new flapper doors from Dorman. Also be aware that 2003-2004.5 had evap sensors located in the wrong position on the evap which also made for poor performance, but the sensor is no longer available. I had to relocate my original evap sensor to new evap in the proper location and AC is working better now than it did in 2004.

 

[ScottLewis]

As shown in my sig,. the truck is an '06. I haven't located the problem yet although I'll pull the dash and do a full flap replacement if it comes to that. So far I've been doing a lot of studying and planning. My next step will be to follow the diagnostic procedures outlined in the Service Manual. I just hate the idea of evacuating the A/C and all that unless I really have too.

 

[Tuesdak]

With the AC on feel the AC evaporator pipes at the firewall. Both should be nearly the same "cold" feel. Careful you don't grab a hot heater hose/pipe. IR temp guns are a safe way to check.

If one evaporator pipe is warm: the R134A charge is low. Same temp of cold means a blend door is broken. You could have both problems at once.

 

[ScottLewis]

OK- both refrigerant tubes are ice cold. Today, all vent positions are working as they should and now the air coming out is frigid. I was able to watch the recirc. door operate when the button was pressed and it looks good. I can see the mode door actuators working also but not the doors themselves. Because the temp can be changed with the levers, it looks like the blend door is OK.

Big Horn just posted on Tuesdak's excellent recent thread about high pressures caused by a weak fan clutch. I didn't realize I was pursuing basically the same issues. I will arrange to have my system evacuated and refrig. weighed to determine if loss has occurred. At 13 y/o, it may be time to replace the fan clutch.

 

[cwbyinjeep]

OK- both refrigerant tubes are ice cold. Today, all vent positions are working as they should and now the air coming out is frigid. I was able to watch the recirc. door operate when the button was pressed and it looks good. I can see the mode door actuators working also but not the doors themselves. Because the temp can be changed with the levers, it looks like the blend door is OK.

Big Horn just posted on Tuesdak's excellent recent thread about high pressures caused by a weak fan clutch. I didn't realize I was pursuing basically the same issues. I will arrange to have my system evacuated and refrig. weighed to determine if loss has occurred. At 13 y/o, it may be time to replace the fan clutch.

I had to find a dealer with fan clutch on the shelf 3 weeks ago at the national warehouses were backordered for 6-8 weeks at that time. Athens Dodge in Athens, GA had 2 until I bought one. I'm changing it out next week on a 2003 as a preventative along with fresh rad hoses. Had an upper hose swell and get cut by belt last week.