97 Q45 a/c unit malfunctioning

[charmessence]

Hello All,

I am new to the scene and would like to send out a shout to all nissan/infiniti owners.

The issue I have been having is w/ my 97q45 in which I have been experiencing issues with the ac/heat. I have had the heater core changed, as well as the thermostat. I have read the informative posts by many of you who have experienced the same issues with your models of the Q but am unable to actually find a fix for mine. My 97 q45 blows out cold air and that's no whether if the temp is on 65 or 85. Also note that I had the a/c unit changed as well (above the radio). Further, when switching the temp from 65 to 85 and vice versa I can hear the blower motor operating correctly and have removed the radio to see that it is functioning as well as looking beneath the driver side to see this as well. Additionally, when I press on the radiator hose the car actually will get warmer if placed on the 85 degree position.

Any advice and help is definitely appreciated.

[Skibane]

Air bubble trapped in one of the heater hoses or the heater core, maybe?

Coolant refilling procedure:

[charmessence]

Thanks for your response and advice Skibane.

I have actually had the system vacuumed to remove possible air bubbles so I am banking on there were none in there as of now. I will say that I did not use the Nissan antifreeze coolant and instead went with the autozone/advanced auto equivalent store brand. Do you think using the auto-zone/advanced brand equivalent coolant would matter?

[Q451990]

I will say that I did not use the Nissan antifreeze coolant and instead went with the autozone/advanced auto equivalent store brand. Do you think using the auto-zone/advanced brand equivalent coolant would matter?

I don't. If you went with something that's not silicate-free, you may be doing long term damage, but it shouldn't be causing this.

Heath

[Skibane]

If the air-mix door is stuck, it may not allow any airflow through the heater core (air will flow around it instead).



Have you tried the climate control self-diagnostic mode to confirm that all the air doors and climate sensors are working properly?

[charmessence]

Thanks Health/Q451990 and Skibane for your assistance.

I have not tried the climate control self-diagnostic mode for confirmation on all of the air doors and climate sensors but will search on how to do that today and get back with you as soon as I find out out to do so.

[Skibane]

Obtaining a genuine Infiniti factory service manual (or "FSM") would be a HUGE help.

It's available for download for free, or you can buy one on CD-ROM for cheap on ebay.

Without one, you typically spend a lot of time guessing about the cause of the problem, or spend a lot of time online researching the fix for it. Unless you plan on relying on a dealer or independent mechanic to fix and maintain everything, you really, really, really, really need one.

[charmessence]

May sound like a simple question but when you refer to the FSM is this the same as the owner's manual?

[charmessence]

Obtaining a genuine Infiniti factory service manual (or "FSM") would be a HUGE help.

It's available for download for free, or you can buy one on CD-ROM for cheap on ebay.

Without one, you typically spend a lot of time guessing about the cause of the problem, or spend a lot of time online researching the fix for it. Unless you plan on relying on a dealer or independent mechanic to fix and maintain everything, you really, really, really, really need one.

Thanks Skibane!

I found one for free online and am looking over the HA section. Is there somewhere (page) that I should look specifically or try first?

[Skibane]

My FSM is for the 2000 model year, so it's probably a little different than yours. What you're looking for in the HA section is "Self Diagnosis", which will include instructions for turning on the self-diagnostic function so you can see if there are any trouble codes displayed.

[charmessence]

Thanks once again Skibane!

Ran the diagnostics and the error codes 26 and 27 came up which indicate air mix door and bi-level door issues. I am now trying to research a way to get to the bi-level door. Do you know if this requires breaking down the entire dash unit?

[charmessence]

I will say that I did not use the Nissan antifreeze coolant and instead went with the autozone/advanced auto equivalent store brand. Do you think using the auto-zone/advanced brand equivalent coolant would matter?

I don't. If you went with something that's not silicate-free, you may be doing long term damage, but it shouldn't be causing this.

Heath

Ran the diagnostics and the error codes 26 and 27 came up which indicate air mix door and bi-level door issues. I am now trying to research a way to get to the bi-level door. Do you know if this requires breaking down the entire dash unit?

[Q451990]

I really don't know on your version of the Q. I'm guessing you'd have to take the glove box out at a minimum. There should be some diagrams in the service manual. By the way, it's available right here on NICO at www.nicoclub.com/FSM/

If I remember correctly the 1997 manual is incomplete, but the 1998 version should be essentially the same.

Heath

[Skibane]

Ran the diagnostics and the error codes 26 and 27 came up which indicate air mix door and bi-level door issues. I am now trying to research a way to get to the bi-level door. Do you know if this requires breaking down the entire dash unit?

I'm not sure, but it looks like the Bi-Level Door Motor is behind the Auto Amp (what you referred to as the A/C unit)...



...so it might be accessible by pulling the radio and Auto Amp out of the dashboard.

Is it possible that the connectors on the Door Motors were disturbed when the Auto Amp or heater core were replaced? Also, several of the wires on the Bi-Level Door Motor and Air Mix Door Motor go to the Auto Amp, so a loosely-seated connector on the Auto Amp itself could cause the problems you're seeing.

[charmessence]

Ran the diagnostics and the error codes 26 and 27 came up which indicate air mix door and bi-level door issues. I am now trying to research a way to get to the bi-level door. Do you know if this requires breaking down the entire dash unit?

I'm not sure, but it looks like the Bi-Level Door Motor is behind the Auto Amp (what you referred to as the A/C unit)...



...so it might be accessible by pulling the radio and Auto Amp out of the dashboard.

Is it possible that the connectors on the Door Motors were disturbed when the Auto Amp or heater core were replaced? Also, several of the wires on the Bi-Level Door Motor and Air Mix Door Motor go to the Auto Amp, so a loosely-seated connector on the Auto Amp itself could cause the problems you're seeing.

Thank you again Skibane!

I am going to take the radio and Auto Amp units out tomorrow and let you know what I see. I do know that the air mix door motor is below the steering wheel and I'm hoping I can get something corrected quickly!

[charmessence]

I really don't know on your version of the Q. I'm guessing you'd have to take the glove box out at a minimum. There should be some diagrams in the service manual. By the way, it's available right here on NICO at http://www.nicoclub.com/FSM/

If I remember correctly the 1997 manual is incomplete, but the 1998 version should be essentially the same.

Heath

Thanks Heath!

I have the FSM downloaded and am looking to find the bi-level motor. Your input has been of great assistance, if you find anyone else that knows if I need to tear down the entire dash to get to the issue let me know!

[charmessence]

Ran the diagnostics and the error codes 26 and 27 came up which indicate air mix door and bi-level door issues. I am now trying to research a way to get to the bi-level door. Do you know if this requires breaking down the entire dash unit?

I'm not sure, but it looks like the Bi-Level Door Motor is behind the Auto Amp (what you referred to as the A/C unit)...



...so it might be accessible by pulling the radio and Auto Amp out of the dashboard.

Is it possible that the connectors on the Door Motors were disturbed when the Auto Amp or heater core were replaced? Also, several of the wires on the Bi-Level Door Motor and Air Mix Door Motor go to the Auto Amp, so a loosely-seated connector on the Auto Amp itself could cause the problems you're seeing.

Been working on the heat and MAF on the q over the weekend..... Have not found anything yet but wanted to note that I disconnected the Ambient Sensor and the car actually started to get warmer not sure why though. I am still working to figure something out any ideas or info would be greatly appreciated (got the MAF cleaned and runs like a champ! thanks to those who posted procedures on cleaning the MAF!)

[charmessence]

Ran the diagnostics and the error codes 26 and 27 came up which indicate air mix door and bi-level door issues. I am now trying to research a way to get to the bi-level door. Do you know if this requires breaking down the entire dash unit?

I'm not sure, but it looks like the Bi-Level Door Motor is behind the Auto Amp (what you referred to as the A/C unit)...



...so it might be accessible by pulling the radio and Auto Amp out of the dashboard.

Is it possible that the connectors on the Door Motors were disturbed when the Auto Amp or heater core were replaced? Also, several of the wires on the Bi-Level Door Motor and Air Mix Door Motor go to the Auto Amp, so a loosely-seated connector on the Auto Amp itself could cause the problems you're seeing.

Hey Skibane.

The picture you have there with the labeling of the bi-level motor is actually the Rear-Vent Door motor according to the 98 FSM (that's if I am reading it correctly on HA-99. I'm still searching for something to get that heat kicking in as it snowed here, outta nowhere, in Raleigh, NC. Let me know if you have any ideas and thank you for your help thus far.

[Skibane]

There should be a series of electrical tests in your FSM for checking the operation of the Local Area Network (LAN) that controls your Bi-Level Door Motor, your Air Mix Door Motor, and your Mode Door Motor. You should probably do these tests before you tear into the dashboard to remove the motors, especially since all of these motors share the same electrical connection to the A/C Auto Amp. The fact that two of those motors apparently quit working at the same time is very suspicious, and strongly points to a problem other than in the motors themselves - i.e., an electrical connection problem in the harness or at the A/C Auto Amp.

In my 2000 FSM, the tests start on page HA-80, and continue for two additional pages. The first page looks like this:

[charmessence]

Thanks for the reply Skibane.

As far as testing the voltage I do not have the equipment to do so. I am going to try to see if I can possibly use one at autozone or advanced in the mean time. If anybody here is in the Raleigh,NC area and is willing to lift a helping hand I would highly appreciate it.

[Skibane]

The only equipment you need for performing the tests is a volt meter or Digital Multi Meter (DMM).

You can pick one up at Radio Shack for under 15 bucks - Harbor Freight sells this one for under 6 bucks:



A DMM is another one of those must-have items for keeping your Q running - Can be used to trouble-shoot all kinds of electrical problems, and is also useful for repairing appliances and wiring around the house. The first time you use it to fix something, it pays for itself.

[Q451990]

Ha... I have one of those HFT ones in my truck! It was free with a coupon and actually works pretty well for answering questions like "is this alternator charging?" and "did I get the right breaker turned off?"

Certainly not precision equipment, but good enough for most things...

Heath

[charmessence]

How can I find an infiniti tech in the Raleigh area looking for some work off the books or does anybody know one?