Question '01 Sequoia Rear A/C blowing hot air - Toyota Tundra Forums : Tundra Solutions Forum

Speedy.Gonzalez · #1 (**permalink**) 06-10-2009, 05:31 PM

My '01 Sequoia Ltd is blowing hot air out the vents in the rear seats and cold air out the front vents. I've tried using the front dash controls and using the rear controls but the rear a/c still only blows hot air. I'm assuming there's only one compressor and it's working properly since the front vents still blow cold. Any ideas?

JBH1989 · #2 (**permalink**) 06-10-2009, 11:23 PM

Could be a stuck heater water valve for the rear air. Big question would be is the rear air dehumidified? I'm not sure if you can access the refrigerant lines under the vehicle, they may pass into the body at some point. See if you can find metal lines under the right rear of the vehicle. With the engine running and a/c cycled on, one line should be near boiling and one should be near freezing. (Don't confuse it with the heater lines--they both will be very very hot). The input is hot and the output is cold (you'd think it's backwards). That will tell us if the refrigerant level is an issue. How cold do the front vents blow? If you run it on max cold for awhile does the shifter feel like an ice cube?

Try accessing the rear air system.

Quote:

Originally Posted by AllData

1. REMOVE REAR SEAT OUTER BELT FLOOR ANCHORS
2. REMOVE BACK DOOR SCUFF PLATE
3. REMOVE REAR DOOR SCUFF PLATE RH
4. REMOVE REAR WINDOW SIDE GARNISH
5. REMOVE REAR QUARTER TRIM PANEL RH

There are two heater hoses connected to a valve. Have someone operate the rear air controls, cycling it between max hot and max cold and see if it is switching. I can't find detailed information on the rear air for this particular truck, so I'm giving kind of a generic approach.

Ray · #3 (**permalink**) 06-11-2009, 08:44 AM

Experience with other vehicle when vents blowing hot air and the other blowing cold air, then your refrigerant is low or you have leak.

Speedy.Gonzalez · #4 (**permalink**) 06-15-2009, 11:30 AM

My wife just got back in town with the Sequoia and I double checked her diagnosis. Sure enough blazing heat being pumped out the rear vents and freezing cold out the front vents. That being the case I doubt it's low on refrigerant. The front actually blows cold enough to cool the rear after 5-10 mintues (if i leave the rear system off). Not 100% sure if the rear heat is dehumidified, but pretty sure it is. I'll have to try JBH1989's method of inspecting the rear a/c system. I'll let you know how it goes.

I'm assuming all of the trim panels and the scuff plates are in the rear cargo area. Is that right?

JBH1989 · #5 (**permalink**) 06-17-2009, 01:37 AM

I don't think it's a refrigerant issue. Sounds like it's in the heater control since it's blazing hot not lukewarm. If the cooling system is semi-neglected, crud can build up and cause the valves to stick.

All the trim panels are on the back right. It's the finned panel.

bretsuaz · #6 (**permalink**) 06-21-2009, 12:48 PM

Were you able to figure out what the problem was?

sodamark · #7 (**permalink**) 06-23-2009, 10:46 AM

Hello, I was having a similar issue, I believe, with the rear air not blowing properly when expected. I tool JBH1989's advise and pulled the rear passenger panels off. I was able to pull off the tube that leads to the floor vents and noticed that here is a little white shaft that has a gear on it. When you push the buttons on the center control for rear roof, rear-bi-level, od rear-floor, that gear spins and moves a little damper. You can see the end of the white shaft on the front of the blower assembly. If you reach behind the blower/heating/cooling assembly(against the sheet metal), you can feel a mechanism that actually helps move the damper gear. Mine was stuck open to the floor position. I had my son push the roof vent button on the console, and gently prodded the mechanism behind the blower assembly, and that seemed to help get the damper moving again.

That does not necessarily solve the hot air issue, but, it does mean that things can get stuck as 1989 suggested. The only problem I've got now, is that the damper only moves from floor to bi-level position, but never fully roof vents. So perhaps, I need a recharge, or there is something that requires more adjustment. In any case, at least there is air coming in from the roof vents now.

Speedy.Gonzalez · #8 (**permalink**) 07-02-2009, 01:17 PM

I haven't pulled the panels off yet. I took the truck in to the dealer for an oil change since i had a coupon for a $19.95 change and asked them to take a look. they are guessing it's a blocked evap coil. they gave me an estimate of $1,300 to replace the fan & evap. they said it was an 8-hour job. their estimate write-up didn't give me too much confidence since it said "possible blockage". I'll strip off the panels myself and look at the areas jh1989 mentioned before i let them touch it (and even then i might take it to another dealer for a second opinion first).

DocPain · #9 (**permalink**) 07-05-2009, 07:54 PM

I've bought some hose covering for the winter, those long pipe covering for about 5 bucks. In addition, aluminium foil tape like material. I've wrap both the high and low side as far as I could. Yup, I does cool the the car down quite a bit.

Also, try to hose down the front radiator and condensor at least once a week with a garden hose..my old mechanic taught me. You'll be suprise these overlook area.

Speedy.Gonzalez · #10 (**permalink**) 07-31-2009, 09:17 PM

I pulled the panels off and the rear control valve seems to be working. Now that I tried the rear a/c when it's not so hot (at night) it seems to be blowing room temp air (and not hot air).

I was told to check the expansion valve to see if it was blocked. Anyone know where I can locate the expansion valve for the rear a/c? is it behind the dash or in the rear near hatch door on the passenger side?