blower motor works, ac cools and blows fine,

when i move the temp from cool to hot it doesnt change. i got another ac/heater control unit from a junk yard, same thing. not sure it may also be defective or not but im wondering what else it maybe. this year 97 doesnt have a valve on the heater hose like i have seen on some of the 95/96



any input appreciated

 

Your story is exactly like mine except that I have full heat all the time. Since another control unit didn't work for me either, I am looking at the Air Mix Door Motor. Starting with the 4th gen, Nissan stopped using a valve in the heater core water line. They now control the heat by either routing the air through the heater core or bypassing the heater core. This is the function of the Air Mix Door. The temperature control lever (assuming you have manual controls) sends a voltage to the Air Mix Door Motor and it opens or closes a door fully or partially.

The only problem with checking the Air Mix Door Motor is that you can't get to it, you can't see it. If you go in the driver's side foot well and remove the panel that gives you access to the ECU, you are real close. The motor is attached to the bottom of the air duct work, right above the ECU. If you look above the ECU on the plastic air duct, you will see a 3 wire harness running sideways with a connector towards the rear of the car. This is the Air Mix Door Motor wire connector. If you can take the ECU out, you can probably take the motor off.

I can't get my ECU out because the wire harness is so packed in there that I can't get to the screws. Maybe you'll have better luck.

 

you think you can post a diagram identifying this "motor" youre saying its behind the center console above the ecu? would like to see what it looks like so i can pull one our at the yard and replace it, i know the ecu is a pain to remove,but i may endup just cutting it out totally since its almost time to install emanage and having the extra lenght in the cabling will help lol

 

Here's a photo taken from down in the driver's footwell.



If you want some drawings, get the fsm and look at pages HA-38 and HA-58.

If you don't have a manual, get one here -

http://www.nicoclub.com/FSM/maxima/

and click on the year desired.
The file named fwd.pdf is the chapter index file for the rest.
The file named idx.pdf is the alphabetical index file for the rest.

 

wow looks tight as sh8t in there .... eeek!

 

I will have to start working on mine again since the weather is warming up and I don't need maximum heat. I am wondering if maybe the arm from the motor that moves the door could be jammed on the ecu wire harness, so one of these days I will work on it some more. I think Nissan's intention is that you pull out the dash and everything to get to the motor.

If you look at this parts diagram, I THINK the motor is # 38, Actuator Air Mix Nissan # 27732-40U00.

http://nissan4u.com/parts/maxima/us_...llustration_4/

 

thanksfor the feedback, im betting my money on that sh8t beign the issue. and it def looks like a roya pain. thankfully its starting to warm up and i have a few moths to get it squared away. almost scared as to how much the dealer would want to change that part out lol

 

sorry to jack this thread lol okay my heat only works when i'm driving...like i'll let the car warm up and i'll turn the heat on but it only blows cold air until i start driving..what could that be!!

 

Typical coolant level in the engine is low symptom. When the engine is cool, remove the radiator cap and check. The radiator should be totally full. If not - well.... Start checking for leaks. Radiators in our cars have a nasty habit of leaking.