A/C Problem, Possibly Frozen-up???

[Buffalo]

Yesterday, a couple of friends & I drove up to the Mountains. About an hour into the trip, the A/C started acting-up.



I had the A/C on "recirculate, high & low", & it was working fine. Then, it started to warm-up, quite a bit, in the truck. Turned the blower up, all the way. Fan worked fine, but, a definate shortage of cold air. Just cool & not comfortable in the truck, at all.

I live in Phoenix (desert). The area I was in had rain the night, before. So, the humidity was a bit high but, nothing like what you guys in the Midwest & Southeast see. Temps. were in the mid 90's so, it wasn't too hot (for AZ. ).



When we got to higher elevation, I turned the A/C off. About ten minutes later, I put my hand in front of the dashboard outlet & cool air was still coming out of it. Later, the dash temp became the same as the outside temps. That's why I think it may have frozen-up.



About a month ago, I had to have the entire A/C compressor replaced. The A/C seemed to work, alright, until now.



On the way back from the Mountains, I turned the A/C back on but, this time taking in outside air (not recirculating). The A/C worked fine.



My friend thought I might be a bit low on R-134a refrigerant.



Any thoughts from the experts would be greatly appreciated. It was 111 deg's. yesterday & is going to be HOT for the rest of the Summer. Don't want any more problems.



My old '91. 5 W-250 never gave me any A/C problems til last year. And then, it was just low on refrigerant. This new truck is getting expensive & kind of tempermental.



Thanks.



Joe F. (Buffalo)

 

[COBRAJET]

Likely a sticky expansion valve or poor placement of the low temperature bulb on the face of the evaporative coil... a common 2003 problem. It could be freon which is the easiest to check. I had hell with my 2003 AC. It constanty froze up on low speeds moderate temps until they replaced the entire evap assembly.

 

[rbattelle]

I agree with cobrajet about the R134a charge level being the easiest thing to check first. Then go from there if you don't get satisfaction.



It's working okay now, right? If so, it might have been the freezing problem.



-Ryan

 

[jelag]

My 04 has 190K miles. . up until last week it has worked fine... . as I drove across the desert last week at 110* it did the same thing... I'd shut down the compressor. . and it would blow cold air for 10 min or so... . once the air warmed I'd turn the compressor back on... .



I have a small temp gauge so I checked the temp. . it would chill to 37 to 40 *'s and after 15 min or so would climb to 50 *s and the air flow would drop to 20% or so... . I assume its freezing up...



It goes in next week for repairs... . when it returns from Canada. .

 

[Elite1]

Last year my 03' did the same thing, it froze up and wouldn't blow cold. The dealer said it was over 1K to fix it & it wasn't covered under my extended warranty! Just for the heck of it I bought some R134a and added some. It did the trick & has been fine ever since. Many 3rd gen's have had the same problem, try adding some, I'll bet it takes care of your problem.

 

[Cory]

Kinda irrelavant but, R134a is not considered Freon. R-12 which was before R-134a is Freon. Just FYI.

 

[DPKetchum]

Lots of threads/posts on this subject. There is a MEMO from D. C. for relocation of the fin temp sensor to prevent freeze up of a fully charged system. Starting in 05 it is on a NEW location on the evaporator.

 

[Buffalo]

What & where is the evaporator?



Can I move the sensor bulb or is that something an expert has to do?



Thanks for the replies!!!!!



Joe F. (Buffalo)

 

[DPKetchum]

Dash R&R which for the experianced is not a biggy. Its in the heater/ac Box its the thing that the blower fan blows through to get cold air to you. The fin temp sensor is basicly the thermostat. D. C. sent a MEMO to dealers if a freeze up problem to relocate it still on the evaporator of course but to a differant location. So many fins over/up/down etc.

 

[dlanza]

Mine did the same thing. I stopped for gas and saw some ice drop off the truck on to the ground. After stopping long enough for ice to thaw the A/C worked fine. Fan blew air now.



Sounds like a defect. Should be a recall. Why do we only notice this problem when it is too late for Warrantee. arggg!



Anyone have the link to the Memo from D/C? I would like to read up and get an estimate to fix or find detailed instructions if possible.

 

[DPKetchum]

Memo was NOT public. Went to dealers for techs encountering this issue. Mentioned this to the tech working on mine last year. He call STAR(tech assist)they were aware and gave him info on where to relocate fin temp sensor. If YOU order a new evaporator the fin temp comes on it in the NEW location. Its also relocated on 05 ups.