mega cab ac sucks!

[tobaccogrower]

system is fully charged and its bairly cold on full blast. also, my truck sounds like a school bus because the fan is fully engaged all the time untill i hit 40mph. is this normal for a mega cab or should i take it into the dealer? its pathetic that my 1993 dodge has 10x colder air then my mega cab!

 

[AEdelheit]

The factory compressors are pretty crappy, I put a four seasons compressor in my mega and it worked way better then new

 

[justme]

AEdelheit, when you stated "way better" does that mean faster cooling, cooler temperatures (38-42 degrees) than OEM, or ...

I am looking to improve the cooling qualities of my Mega cab, but I am content with the 38-40 degrees blowing from the vents to date.

What is the cost of the compressor you purchased and from whom?

 

[goodguys75]

system is fully charged and its bairly cold on full blast. also, my truck sounds like a school bus because the fan is fully engaged all the time untill i hit 40mph. is this normal for a mega cab or should i take it into the dealer? its pathetic that my 1993 dodge has 10x colder air then my mega cab!

yes very normal... try living in vegas heat with that a/c

 

[WOT]

Mine works pretty well - only complaint is the compressor really "clunks" when it is kicked on, but otherwise nice and cold. A buddy has an '06 Mega and his died and went through 2 compressors and it never worked as well as new. He took it to a guy that a bunch of people recommended as an AC guru and whatever he did worked like a charm. I guess the moral of the story is a good AC guy can make it work well and stay away from the "average repair guys. "

 

[wcjp]

Are you sure the HVAC doors are working properly? My Mega works great in high heat with wife, daughter and two dogs.

 

[AMink]

This is a weak spot. Mine is barely adequate on hot (90°+ days), especially if it's been sitting in the sun. The air is barely cold and the volume is pathetic. On 4, my fan doesn't move nearly as much air as my Chevy work trucks. The A/C in those could spit ice cubes. I think it is an undersized unit for the space in the cab of the Mega. Do a search and you'll find there are several threads on here about it but I don't know if there is a good alternative. Maybe moving north.

 

[tobaccogrower]

40* air ? i get mid 70's. think i need to make an appt

 

[AEdelheit]

AEdelheit, when you stated "way better" does that mean faster cooling, cooler temperatures (38-42 degrees) than OEM, or ...



I am looking to improve the cooling qualities of my Mega cab, but I am content with the 38-40 degrees blowing from the vents to date.



What is the cost of the compressor you purchased and from whom?

Ahh, my stock compressor would push about 50 out the vents, and tool a long time just to get there, once I put the four seasons in it pushed about 40 and got there quicker. It also eliminated the loud clunk when the compressor engaged. I don't remember where I got it or how much it was though.

 

[mwilson]

This is a weak spot. Mine is barely adequate on hot (90°+ days), especially if it's been sitting in the sun. The air is barely cold and the volume is pathetic. On 4, my fan doesn't move nearly as much air as my Chevy work trucks. The A/C in those could spit ice cubes. I think it is an undersized unit for the space in the cab of the Mega. Do a search and you'll find there are several threads on here about it but I don't know if there is a good alternative. Maybe moving north.

Moving North won't help, it still gets hot enough for a few summer months to need A/C in my Mega Greenhouse.

Illegal to tint windows up here anymore than pretty much stock so if the sun is out front or to your left you simply simmer along.

Was very jealous to see the Megas in Indiana with all blacked out windows. If I tried that up here I would get thrown in jail.



A/C has been borderline since day one, noticed this year it seems a little worse so probably an ounce or two has escaped in 6 years. I will bring it down here some evening and put the new Snap-On super-sucker on it to see how much was in the system.



It is indeed a pitiful thing that my '97 will put frost on your nose to this day, and the Mega Cab that is a 9 year newer truck has such an undersize, underperfoming system.



Mike.

 

[GCroyle]

Guys,



I'm not an AC'ologist, period. BUT it seems to me that at least on my '05 that there is a significant air gap between the condensor/intercooler and radiator, several inches all the way around in fact. So as our electronic fan tries to pull air across all of that stuff (me thinks expecially at slow speed going thru stop lights) that our airflow across the condensor is minimal. What did I do, for the second season I had made a bit of a duct effect with some duct tape across the top closing the air gap, foam pipe insulation wedged in the sides to close them off and beta testing some antifreeze jug panels cut to fit on the bottom to route air thru the heat exchanging parts rather than taking a short cut and bypassing. Too soon to roport on the latest results. Also my truck needs engine heat to get the fan moving air, at cold idle it is just turning very lazily.

It is not 100% sealed still have gaps ans such. I think my neighbors '11 C&C work truck has at least a top duct panel IIRC.



YMMV

 

[mwilson]

beta testing

Oh, I like that.



Mike.

 

[GCroyle]

Mike,



It should work, the jugs panels were from ZEREX G05, spec'd as OE use.



That drain plug is a PofS!!!!!!!!!!!!!!

 

[mwilson]

Mike,



It should work, the jugs panels were from ZEREX G05, spec'd as OE use.

That is logic I can agree with... ... ... .



Now if we don't inadvertently start a war regarding which brand of jug blocks air the best or making sure that you cut with the grain of the plastic ... .....



Mike.

 

[GCroyle]

Mike,



I needed that laugh, thanks.



Pic's tomorrow maybe. This morning wasn't much of an AC test, tonight will be a decent test.



But really isn't it like a leaking duct, air ain't going where it could?

 

[mwilson]

Mike,



I needed that laugh, thanks.



Pic's tomorrow maybe. This morning wasn't much of an AC test, tonight will be a decent test.



But really isn't it like a leaking duct, air ain't going where it could?

You may be right, a very effecient, intelligent fan and clutch working against a poorly sealed condensor/intercooler/radiator. Too much air sneaking in around the gaps.



Mike.

 

[JFought]

i can feel the difference when 1k rpm and run my had around the gaps.
I can really notice where it pulls from and where it is reduced. it still holds a paper the the condenser but when you move it nerar the top of the radiator it flops around a lot (lots of suction!)

I wish i could sneak a fan in frt of condenser or fill the gaps to get more suction thru the condenser

 

[GCroyle]

Last night (90 degree ambient) I got stuck in stop and go for a while and as the engine was still getting up to heat, the AC was working but nothing to brag about. When traffic hit the speed limit and the engine was up to temp things got better when I put it on recir the DS dash vent thermometer was in the mid to low 40's, not bad.



Seems like engine up to temp is very important (correct at any time guys) cause the computer wants a hot engine for emissions and performance, then AC comes later. Compare your start up fan volume vs a hot engine volume, mine is really different. Had AC checked at dealership couple of years ago with complaint of poor AC as you go thru stop and go, they checked didn't find anything they could fix.



None of my ducting actually blocks air flow IMHO it just routes the air across the intended heat transfer devices. I've just closed off some BIG gaps that allowed lazy air flow.



What say you?

 

[EMAC2]

This is a current problem with the fourth gens too. compressor high side cut off is actually shutting off the AC compressor because the fan doesn't pull enough to cool the refrigerant. Lot's of complaints on the other forums, but it does appear to be hit or miss... .

 

[Wertles]

Same issue. It takes a good 1/2 hour of driving to get the truck comfortable. I researched right after I bought the truck new in 06. I had the dealer check it out. Everything was in spec. Seems like the census was that the original ac system was great in the single cab trucks, fine in the quad cabs and terrible in the Mega Cabs. The system was just not designed to handle the additional space and glass of the MC. They put a bigger system in when they switched to the 6. 7.
I have nice cold air coming out the vents but am still uncomfortable, especially when the sun is coming through the drivers side. Some have had luck with AC additives making the air just a little colder than stock.