Mega cab Weak a/c

[JWilmer]

I can deal with this A/c issue...



BUT my HEATER better work this winter..... LMFAO-BJ

 

[Vaughn MacKenzie]

Not to change the subject... but 95 degrees and 90% humidity never exists. The heat index if possible would be over 140 degrees. 95 degrees with a heat index of 105 would be around 50% humidity. It is very difficult to have temps rise without a lowering of the humidity. It is the most humid early in the morning since the temps usually fall at or just above dewpoint which is as humid as it gets. A heat index of 105 is very uncomfortable.

Cobrajet is correct. . . here is a Heat Index calculator http://www.srh.noaa.gov/elp/wxcalc/heatindex.html



With 95F air temp the humidity would only be 50% to get a heat index of 105.



How about 109 degrees with 37% humidity? That's what we had in Pasco Washington one recent summer. Got an inch of rain, two days later it hit 109, and the humidity had only fallen to 37% when we the mercury peaked out. Next day's paper reported it as a brain-melting heat index of 128 You literally couldn't handle being outdoors for more than a few minutes at a time.



Vaughn

 

[Walker]

Mr. Tracy aka S. King. Excellent work. Mas details por favor. Wiring schematic, type of synthetic and additive (any brands better than others?).

 

[sonorakitch]

The very dry climate in AZ. is helping your AC out quite a bit. It is a lot easier to cool dry air. It is a lot easier to heat it as well. You are 110-115 in the daytime and still fall into the upper to mid seventies at night. It was 104 here today with a low of only 83... hotter than that in the city. You are getting a nice 30-35 degree swing. We are lucky to get 20... high humidity. The temp can not fall below dewpoint so we wake up to nice muggy mornings... working the AC right off the bat.

In Phoenix, because of the "heat island effect" we have created, it no longer cools off in the evening. Tonights high is going to be 90 degrees!



~Chris

 

[NKenny]

The town of Yuma, AZ in which I grew up, would be 104 at 3am. Try that on for size. Additionally, all of the areas in Southern Arizona are surrounded by irrigated farm land were heat indexes can reach into the 150 degree range. That kind of heat will make you puke.



There is plenty of strain on any AC unit, especially my Mega Cab (which is, by the way, in the shop for a check engine light and a side inspection on a loose front end and no-blow, no cold AC).

 

[blacksmoke10]

SKING



Any update on how to inrease blower voltage?



thanks

 

[DPKetchum]

Or to get those BELOW freezing temps on how to by pass the Fin Temp sensor so the compresser stays engauged and then how to keep the evaporator from freezing up once the fin temp is bypassed.

 

[CCool]

A/C Problem

Ok. guys here I go. I have the same problem you all have, 3

gen. weak A/C. I have been thinking a lot about this and have a different Idea. Please feel free to tell me if I'm on to something or way off. I will start by saying my friends all have 2 gen's and thier ac is like a meat locker. In looking at this, all of the componets in the front ie. A/C evaporator, intercooler, radiator are all stacked one in front of the other. In the 3 Gen. trucks there is a huge gap between the intercooler and the radiator and if you stick your hand in between the two with the truck running you can feel the air being pulled around the a/c evaporator/intercooler instead of through it.

With the truck running down the freeway 75- 80 MPH. the a/c will get cold after a while. In bumper to bumper traffic or city driving for get it. On this note I think the gap between the two is allowing the air to be pulled around the evaporator there for not allowing the A/c system to work correctly.

As for the ducting door under the dash that is true, I have broke it twice. It is the pin that connects the control arm to the door that snaps in half. Seen it with my own eyes. When this happens the door closes and blocks the flow of air.

 

[Walker]

Sounds like a possibility. But, how much air flow is there on any units coils at stop and go speeds gap or not?



As for the damper door, when mine broke, it snapped off on the left (drivers) side along the top edge (pivot point) of the door, and not on the pin itself. I ran the actuator a few times between the outside and recirc. settings and watched it spin. After attaching the door back on (which only attaches one possible way because of the grooving) it sure looked like the cam was spinning at a much different position (more down instead of up). Looked like to me the factory install may have been a little off and caused the stress.



S. King still waitin' for the blower and freon BOMBs :-laf

 

[DPKetchum]

Yes and a understanding on how to by pass the Fin Temp sensor and evaporator freeze up issue when you get it below 32 degrees?

 

[gtobey]

Just got an '06 Mega Cab, trading in my '02, and yesterday afternoon the wife made mention that there wasn't a lot of air coming out of the side vent on the passenger side. We took my 2nd gen on a trip out west to West Virginia, Kentucky, Indiana, Missouri, Nebraska, Colorado, Utah, Nevada-121 degrees in the shade at Hoover Dam, Arizona, New Mexico, Texas, Arkansas, Tennessee, Georgia, and back to VA. I had 38 degree air coming out of the center vents (showing on my A/C thermometer) all of the time, regardless of the fan setting. I have not checked this truck as I only have 429 miles on it. We experience a lot of humidity here in VA and temperatures in the mid 90's. I know out west, I didn't perspire a bit, but here at home, you sweat just standing in the shade! Almost as bad as St Louis beside the Mississippi River! I will concur with those that say the A/C is not as good as the 2nd gens.

 

[AMink]

I had mine in for something else and asked them to check the a/c. Said it was working within factory specs. Oh well.

 

[DBoggs]

I noticed that I was lacking in air flow (or so i thought), and very noisy over the last couple days, so I pulled my glove box out and looked at the top of the air box. Sure enough the fresh/recirc door was missing All I could see was the broken piece of the hinge left up where it should have been. I pulled out the blower motor this morning and was able to get the whole door out of the box along with the broken hinge. New door is on its way and it will be fixed in a couple days. Meanwhile since I got the door out of the way my airflow is back to normal, which in my opinion is quite good.



Duane

 

[blacksmoke10]

I would like Dr. Z to ride in my new mega cab in phoenix arizona and tell him if he cant fix the a/c I will let him run into the wall and then he can see a real doctor. I keep seeing the commercials on tv saying how good there engineering is. Funny you could hit a wall and live but I guarantee you you will be sweating when you do it.

 

[Kday]

I've got a 05 QC and I noticed that after I put in the Rokktech advanced timing sensor the A/C compressor would stay engaged longer (not sure of vent temps but I'll check). I'm not sure I'm on track with this but I know it made a difference on mine, maybe someone who knows more than me will chime in. I'm not going to debate temps vs. humidity here but it's plenty hot here in S. E Florida. Good luck on a fix, Ryan.

 

[gtobey]

I've got a 05 QC and I noticed that after I put in the Rokktech advanced timing sensor the A/C compressor would stay engaged longer (not sure of vent temps but I'll check). I'm not sure I'm on track with this but I know it made a difference on mine, maybe someone who knows more than me will chime in. I'm not going to debate temps vs. humidity here but it's plenty hot here in S. E Florida. Good luck on a fix, Ryan.

It's been in the upper 90's and low 90% humidity here in VA. I think that maybe mine cools better while going down the road than it does in traffic or sitting still. That tells me the fan is not pulling enough air over the condensor. I have noticed the gap between the condensor and the radiator, and that there is no seal to bridge that gap. Air can be pulled inbetween the radiator and the condensor and not go over the condensor to cool it. My '02 had a heavy rubber flap under the A/C condensor between the bumper and the radiator. This forced air being pulled in by the fan to go over the condensor. I know this worked because when I went out west to Sidney, NE, to Denver, CO, Vegas, Hoover Dam (122 degrees F), to the Grand Canyon in AZ, all through NM, TX, AR, TN, and back to VA, I had 36 degree air coming out of the center vents, and ran the fan no more that on the second speed while driving. Sure, I ran it on HI for a few minutes, then turned it down, cause my truck was patriot blue. Park it in the sun for 2 minutes and you're dying! It gets HOT inside in a hurry!



Anyone try a rubber flap under the condensor to the radiator? I wonder if it would make any difference?

 

[JWilmer]

OK... went on a "family day" yesterday (alot of stops... alot of open doors... alot of dilly-dallying with 2 young boys)..... heat index was 106 degrees here in MN. (warm enough I think )... full cold... on recirc... . fan on #3... wife complained about being to cold... turned fan to #2... I was OK... still getting low 50's from the center vent... . wife turned her vents up and away (still too cold) wife misses the dual climate control the Chevy had... . kids were fine in back.



AGAIN... I cant complain about mine... . its NOT the coldest A/C I've seen... but it is plenty cool for me and my family... IMHO... .



This was the hottest test temp to date... will leave it alone for now... it did well enough not to mess with it..... BJ

Well today was 110 heat index..... did some errands..... left A/C fan on #2... recirc/coldest temp position = NO problems maintaining a cool cab... . idling/city driving and alot of open doors..... still recovered quickly.



All I can say is "MY" MC A/C works in my climate... . my HEAT better work this winter-LOL-BJ

 

[Kday]

Just an update on temps at idle after a few mile run and time to equalize. Output on center vent closest to driver 45 deg. F outside temp 94 approx humidity 75%.

 

[sag2]

If your door is broken, the part will now supersede to a housing and door with an internal stop to keep it from breaking.

 

[DBoggs]

sag2, what in your opinion is causing them to break? Traveling to far in the housing? I was able to replace my door without removing the housing, dealer warranteed the door only. Seems to be working fine right now. They were 2 weeks out on being able to schedule me for repair and I'm going on vacation so couldn't wait. If it breaks again I'll let them do it next time if a housing is involved.



Duane