First, let me just say that I did search google for my problem

My problem: If I click any functions on my temperature control other than top vents (defroster, feet, feet/defroster), no air comes out of the selected function and a clicking noise comes from the dash. No matter which function I put it on, air still comes out the upper vents.

Pre-existing problems- The following existed before my current problem and I just never did anything about them. Hopefully they help solve the above problem.
1. Gas fumes sometimes come through vents when heater is on.
2. Heat only comes out of left 2 vents.
3. Heat only comes out when I am driving (not when I'm stopped)

EDIT: I have a 1994 Maxima GXE, not SE (I think)

 

Do you have the digital climate controls?

if yes then try diagnosing with this procedure:

-----------------------------------------------

Turn Ignition from off to on,

Within 5 seconds press and hold the off button for 5 seconds.

You can now cycle through each dignostic mode by using the up/down
temp selection buttons. For steps 4 and 5, engine must be running for
compressor to operate. The modes are as follows:

1. LEDs and segments are checked.

2. Input signals from each sensor are checked.

3. Mode and intake door motor position switch is checked.

4. Actuators are checked.

5. Temperature detected by each sensor is checked. Multiplex
communication errors are checked.

6. AUXILIARY MECHANISM Temperature setting trimmer.

Step 2: check the sensors. The code will be shown on the climate
control display. You should perform these tests under sunshine at
normal engine operating temperature. And now for the codes:

20 All sensors are functioning properly

21 Ambient Sensor

22 In Vehicle sensor

23 Thermal transmitter (Thermister) *If engine coolant is low, code 23
may appear even if this sensor is functioning.

25 Sunload sensor *When conducting this test indoors, direct light
(more than 60w) at sunload sensor (Code 25) will indicate malfunction
even if the sensor is functioning propery.

26 PBR

Step 3: check the intake and door switches. Malfunctioning switch
codes:

Mode Door Motor
30 No fault
31 Vent
32 B/L
33 Foot
34 Foot/DEF
35 DEF

Intake Door Motor
36 FRE
38 20% FRE
39 REC

Step 4: check actuators. Press DEF to change test pattern. Nissan has
a grid printed in the book. Here is a rough approximation:

| Mode | Intake | MIX | Bi-Level | |
Code# | Door | Door | Door | Door | Blower | Compressor
-------------------------------------------------------------------
41 Vent REC Full Cold Open 4-5V ON
42 B/L REC Full Cold Open 9-11V ON
43 B/L 20% FRE Full Hot Close 7-9V OFF
44 Foot FRE Full Hot Close 7-9V OFF
45 F/D FRE Full Hot CLOSE 7-9V ON
46 DEF FRE Full Hot CLOSE 10-12V ON

Step 5: Display temperature detected by each sensor:

Use DEF to select sensor, Ambient or In-vehicle sensor.

------------------------------------------------

If your heat only comes on when you are driving, you may have a dying water pump, or the belt might be loose. You should try bleeding your coolant system of all air that could hinder your heat production.

Try the diagnostic procedure then we could see from there.

 

Thank you for the reply, but unfortunately I don't have a digital climate control. I bought the car used and the previous owner didn't have the manuel for the car. I tried going to the online manuel, but as you probably know, the site is down (the one in the sticky topic). My climate control is this one: link

 

there is another site. try www.autozone.com .

Have you had the coolant changed recently?

 

Coolant has not been changed really recently, but it is still good.

 

Try finding the input and output hoses to your heater core. With the engine fully warmed and your heat set to max, feel the two hoses. If both are warm/hot then its not your heater core. If one is hot and the other cold, then your heater core is clogged. At the same time, youll find that there is something connected to one of those hoses. This is the heater control vavle. Examine it and see if its working... see where the arm is, in or out.

 

could it be your blower motor is going?

Hope and pray its not your heater core! man if my heater core ever goes, im just gonna live with no heat. After seeing another .org member post what he had to do to change the heater core out with a new one, i dont think its worth it.

 

its worth it when you are driving around in -10 celsius or colder. Trust me on this..
You spend every moment shivering and the windows do not defrost at all. You can barely see out the windshield and forget seeing your blind spots.

Very dangerous...

 

true, sorry i dont have to worry about that kinda temps. the coldest its gotten here is like 35

 

You could always add an electric heater

 

I assume this heater core is under the hood. (I will ask a friend that knows more than me about where this heater core is located.) And if it is the heater core, then I probably will replace it because it gets cold in the winters here in Texas. Most people think it is always hot here in Texas but trust me, it gets below freezing just about every winter where I'm at. I will try to post back sooner next time.

 

might be your 'mode door motor'
check out my how-to for auto climate control conversion (www.geocities.com/craigbrace) and you'll see a picture of the mode door motor. It's on the left side of the center console, above where the ECU is - about level with the radio but further back. Looking from the drivers side, you'll see a large plastic X looking thing with a motor attached to it. That is what controls the different vent modes. Watch it while you change modes on the control unit and see if it moves freely. I have a feeling that is what could be clicking.

I may need to be replaced or just adjust the linkage.

 

Craig- First let me say that your site is awesome. I found it about 6 months ago and it has become extremely valuable when messing with my car (most recently the window regulator). I actually found this site on your links page. Thank you so much for putting that site up.

You are correct. The white thing is not moving at all when I change the setting on my climate control but when I move the white thing with my hand, it changes the setting. I can't tell what it is connected to right now but I will use your pictures tommarrow and see if I can tell based on them. Which picture is the mode door motor? I moved the mouse over all the pictures and none said mode door motor.

Adroga- I haven't gotten around to checking that heater core yet which I assume is the cause of one of my other problems. Hopefully, I will have time tommarrow to check.

 

At the very bottom, where it shows how to adjust the linkages, it shows the mode door motor there. I guess I didn't include any pics of it in the writeup because you dont have to change it for the swap (just some wiring for it).
The problem could be the control unit not giving the motor the signals it needs or the motor itself is broken. If you can find one at a junkyard (should be pretty easy, and you can get it from an auto or manual climate control car because it's the same), you can test the motor out. It probably wont be too expensive because it's a pretty small part.
good luck

 

Keep us updated on your progress. I just spent the last few weeks diagnosing my lack of heat which I fixed, so I can relates to your frustration.

 

I had the door mode actuator clicking on mine but I disconnected it and the vents still switched etc. I have a heating/cooling control unit that I had bought when mine was doing this as I thought it was the culprit but it wasnt. Its for sale in the classified section for $20.

Since I looked at mine it could be the intake mode actuator instead, Good luck.

Craig, excellent writeup by the way!

 

It has been raining here all day so no progress today. I will update you guys tommarrow.

ADDED: 2/24/04- Still raining

 

tvaddict817,

Let me know what you find out. When I turn on the heat, I get heat out of the two vents next to the instrument cluster, but cold air out of everything else. Same clicking, but not always when switching modes. I'll post anything I come up with.

 

My clicking definately was the mode door motor. I touched it when I switched controls and the clicking was coming from there. I then took out the mode door motor and and opened it up. There were about 7 gears on 3 different pegs. One peg that had 3 gears was broken at the bottom causing the gears not to catch right. I have not replaced it yet but I'll let you guys know what happens after I do.

 

I replaced the mode door motor and all is great now. Thanks everyone for the suggestions and comments.