Acura MDX SUV Forums banner
1 - 9 of 9 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter · #1 ·
Hey everyone, I'm very new to this but have already found some great information on these forums.

I bought a 2001 MDX W/Navi about a month ago and am loving it except my parents got in the back and told me that the rear A/C wasn't working. I found on here that the rear transistor goes out so I replaced that and now have power and a blower! The bad part is that it only blows cold air. It doesn't matter if it's on auto or rear control, the only air I can get out of the rear is cold and not just outside air cold, I mean A/C cold. The heat and everything works great up front.

We are coming into the colder months and would love to fix this, any suggestions?

Thanks
 

·
Registered
Joined
·
2,159 Posts
You can retrieve a code from the rear heater/A/C control. To do this...
1) Turn the rear fan switch to OFF
2) Turn the key to the II position (on, but not running)
3) On the rear controls, press the vent switch, and then the heat switch. Hold them both down until the vent indicator (the light on the vent switch) comes on for two seconds. If that light doesn't blink after the two second "on", there are no codes stored. If it does blink, count the number of blinks and let me know.

FWIW, there are a few things that can cause lack of heat in the rear.

1) Maybe there is no hot water flowing to/from the rear heater core (in the rear of the console). You can test this by laying under the car with the rear heat on high, and the engine warm(ish). You should be able to feel the (obvious) heater lines running coolant back to the rear heater. If just one hose is warm, it would indicate that no water is flowing through the heater core. Neither being warm could indicate the same thing, or that something up front is preventing coolant from flowing back.

2) If both hoses are warm (indicating that hot coolant IS flowing through the heater core), the problem is likely the mode controller or the air mix controller, which flips an internal vent to channel air through either the rear A/C evaporator or the heater core (or some combination of both, depending on the temperature setting). I haven't ever fiddled with these, but it should be possible to hear both of these moving (as they're motorized) when you crank the controls. It would certainly be worthwhile to check fuse #3 in the driver's side under-dash fusebox (7.5 amp).

Troubleshooting would be a lot more definitive if you were to pull off the console to expose the control motors, but I would avoid that until absolutely necessary. You might just want to put a snuggly blanket in the back seat instead. ;-)
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #3 ·
Thanks for the info! I've just done the test and it blinks twice and then goes off, blinks twice then goes off, etc.

The number 3 fuse looks good.

What do the 2 blinks tell us?

Thanks again
 

·
Registered
Joined
·
270 Posts
my manual says that 2 blinks is
'a problem in the rear air mix control linkage, door, or motor.'


In English, there's a motor that moves a door between hot and cold and it appears to be stuck.

Someone here is going to have to tell you how to get to the motor, I don't know how to remove the back console.
 

·
Registered
Joined
·
2,159 Posts
It's not all that hard to get the console off. Fiddly, but just follow the instructions, keep track of which hardware goes where, and it should be cake.



Then, just see what's up with the air mix control. Hopefully it'll be obvious. You might consider finding one on Ebay or a boneyard, to have in hand when you take the console off (so you don't have to reassemble it to order one if it IS bad). Of course, the problem could be a lot of other things - a bad connector, a linkage that fell off, etc. I'll often have the part in hand, and if I don't need it, I'll just re-sell it on Ebay. The one control motor (front vents) that was acting up in my car was fixed by removing, cleaning and re-lubing it. I did also install a very thin washer under one gear to make it run smoother.

Here's how to remove / install the air mix module...
 

·
Registered
Joined
·
2,159 Posts
Check out the (many) links and videos that deal with repairing the mixer and mode controllers. If they "kinda/sorta work", chances are good that a cleaning and relube might return them to their proper operation.

And of course, there is always the boneyard (aka "men's mall") or Ebay approach. I just checked, and it looks like you can get the part used on Ebay for $70-80 delivered (yes, used... so there's some risk). FWIW, neither of the parts listed have the correct part number (one references a blower motor transistor, and the other is listed as incompatible with a 1st Gen MDX).
 
1 - 9 of 9 Posts
Top