Fixing no heat issue is Z32

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KrazyKyle
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Fixing no heat issue in Z32

Postby KrazyKyle » Sat Nov 03, 2007 5:46 am

Hey guys. I have been searching through these forums for over a year now, but I have never made a contribution. I figured I would make one today. I hope this will help out any Z32 owners whose heat or vent control has went out.

Fall last year, when the first cold nights started appearing, I noticed my air wouldn't switch for cool to hot. I figured my heater core might have been stopped up, or the control unit was bad. The unit was pretty beat up. I also noticed that when I tried to switch the vents it would sometimes freeze up and not switch from feet to defrost or any of the other settings. So I ordered a new control unit to replace the broken one. Or so I thought it was broken. When I got the new unit in, that didn't fix the prolblem.

So the next time I had a vacation from work I decided to investigate. I pulled the dash (PITA) and started messing with it. I found out that the motors were seized up that controlled the vent control and the air mix control. I tried to replace the motors from the 91 parts car I had, but it had the automatic climate control so they were not compatible. So I set the air mix to heat manually by moving the heater core control valve. So I would be fine during the winter, but I had to reach under the dash and switch it manually when it warmed back up again.

So now its winter time again, and I'm tired of dealing with no defrost and having to lay in the floor board to change the heat. I ordered the new motors from Courtesyparts.com and installed them yesterday. It was quite an ordeal but it wasn't as bad as the first time I tried to fix it.

Here's the part numbers and prices for the two motors.

27731-30P00 [27733M] Actuator Assy-Mode $76.51(This controls your vents)

27732-30P00 [27733N] Actuator Assy-Air Mix $108.98(This control your heat)


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KrazyKyle
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Re: Fixing no heat issue in Z32 (KrazyKyle)

Postby KrazyKyle » Sat Nov 03, 2007 6:05 am

I started working on the fix about 8:30 Friday morning after I got off work. (I do quality control at the Nissan plant in Smyrna on Night shift by the way.) I removed all the necessary trim and panels, dropped the steering column, and preceded to remove the dash.

This is what it looks like with out all that in there.



You also have to remove the dash bar. This makes it alot easier. Here are the locations of the two motors. The first one is the vent control motor.



This is the air mix motor.

Also this is the heater control valve this is where you can conrol the heat manually. There is a cable that runs from this to the air mix motor. If you removed the cable, you can slide the valve open for heat. Or close it for cool air.



With all that removed you can get to the vent control motor, its not to bad to replace, just have to make sure you don't break any of the plastic arms that connect to the vents though.

Here are the new motors. Vent control on the left, air mix on the right.





The hard one to replace is the air mix motor. I had to unhook my A/C lines and remove the blower motor to have room to fit my and under the A/C unit to remove the motor. If you look in the previous picture its a tight fit under there.



After removing all that it was still pretty hard to replace but I got it done. Then I put it all back together, and now I have heat, but I still have to recharge my A/C to have defrost though.

Pic of the work in progress.



So I hope this helps someone in fixing there heat. I have seen a bunch of posts about it.

Modified by KrazyKyle at 9:17 AM 11/3/2007
Modified by KrazyKyle at 9:18 PM 6/26/2008

Jspeedrifter
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Postby Jspeedrifter » Fri Nov 16, 2007 6:15 am

Great write-up! How hard was it to get to the heater control valve and manually change it from cold to hot? I don't have the time right now to remove the dash and everything, but I need some heat!!

My vents work right and everything, but my heat doesn't work at all. The car has a new heater core, thermostat, and radiator, so I'm pretty sure it's just the air mixture motor.

Thanks for any help!

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Postby evildky » Fri Nov 16, 2007 10:09 am

ouch, this is what i hate aobut these cars, huge PITA to work on

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BigTDogg (MA)
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Re: Fixing no heat issue in Z32 (KrazyKyle)

Postby BigTDogg (MA) » Fri Nov 16, 2007 10:12 am

Nice work Kyle! I hope you replaced your heater core while you were in there. Only a matter of time till that goes too

KarKrazy
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Re: Fixing no heat issue is Z32

Postby KarKrazy » Mon Dec 06, 2010 7:39 am

On the heat control valve, which way is open and which way is closed? Stupis Question I know but just trying to get some heat. And where exactly is the air mix actuator located? Is it behind the heat box or on the side?

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spenka
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Re: Fixing no heat issue is Z32

Postby spenka » Mon Dec 06, 2010 10:38 am

This thread is "heaven sent" or should i say "heat sent" lol. Im having the same trouble on both my z32's. I'm keping an eye on this thread.

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ZXdriver
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Re: Fixing no heat issue is Z32

Postby ZXdriver » Mon Dec 06, 2010 2:12 pm

Hey where do you live if you dont mind me asking.

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Re: Fixing no heat issue is Z32

Postby sroy123 » Thu Oct 23, 2014 5:43 am

Actually the vent control it the one on the right not the left. You DO NOT have to pull the dash to fix the vent control actuator. You do need to pull the seat for more comfort. And a word to the wise. If you are planning on fixing your actuator by pulling it a part for the love of god do not remove the arm. this job becomes almost impossible. however what I am going to try is to set the arm back on as indicated in the above picture and hook it up. But I have to do that in all five selection positions (face, face/floor, floor/window, floor and defrost . hopefully I will be able to get it back on in the correct position. If not I will have to get a new one.

thanks

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KrazyKyle
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Re: Fixing no heat issue is Z32

Postby KrazyKyle » Tue Nov 10, 2020 8:51 pm

So, I have had several members sent me PMs about the pics being missing after Photobucket started charging for hosting. The site won't let me edit my original post, but here is an updated post with pics hosted on Flickr. Hopefully this is still useful.

I started working on the fix about 8:30 Friday morning after I got off work. (I do quality control at the Nissan plant in Smyrna on Night shift by the way.) I removed all the necessary trim and panels, dropped the steering column, and preceded to remove the dash.

This is what it looks like with out all that in there.
Image

You also have to remove the dash bar. This makes it alot easier. Here are the locations of the two motors. The first one is the vent control motor.
Image

This is the air mix motor.
Image

Also this is the heater control valve this is where you can conrol the heat manually. There is a cable that runs from this to the air mix motor. If you removed the cable, you can slide the valve open for heat. Or close it for cool air.
Image

With all that removed you can get to the vent control motor, its not to bad to replace, just have to make sure you don't break any of the plastic arms that connect to the vents though.

Here are the new motors. Vent control on the left, air mix on the right.
Image

Image

The hard one to replace is the air mix motor. I had to unhook my A/C lines and remove the blower motor to have room to fit my and under the A/C unit to remove the motor. If you look in the previous picture its a tight fit under there.


After removing all that it was still pretty hard to replace but I got it done. Then I put it all back together, and now I have heat, but I still have to recharge my A/C to have defrost though.
Image

Pic of the work in progress.
Image
So I hope this helps someone in fixing there heat. I have seen a bunch of posts about it.

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i40webdesign
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Re: Fixing no heat issue is Z32

Postby i40webdesign » Wed May 12, 2021 8:48 am

Thanks for posting this KrazyKyle !!
In my 1990 300zx 2+2 with manual climate control both vent control and air mix motors just died. (May 2021)
I really appreciate the photos.
I'm trying to place where the air mix motor is located based on your photos.
Is the air mix motor near the floor/transmission tunnel on the passenger side of the car?

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KrazyKyle
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Re: Fixing no heat issue is Z32

Postby KrazyKyle » Wed May 12, 2021 12:48 pm

i40webdesign wrote:
Wed May 12, 2021 8:48 am
Thanks for posting this KrazyKyle !!
In my 1990 300zx 2+2 with manual climate control both vent control and air mix motors just died. (May 2021)
I really appreciate the photos.
I'm trying to place where the air mix motor is located based on your photos.
Is the air mix motor near the floor/transmission tunnel on the passenger side of the car?
I actually don’t remember which is which. I feel like the motor that’s on the floor on the passenger side controls the mix and the motor on the driver’s side controls the doors. It’s been a long time.

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i40webdesign
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Re: Fixing no heat issue is Z32

Postby i40webdesign » Wed May 12, 2021 1:04 pm

Ok...well thanks for confirming one of the motors is close to the floor.
Again, really appreciate the post/photos.

AZ300Z
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Re: Fixing no heat issue is Z32

Postby AZ300Z » Tue Aug 24, 2021 5:09 pm

Great post! I am pretty sure my car has the same problem (a/c and auto cc works, but no heat or vent control) but mine is a low mileage (27k) 1990 and at some point without much use, the vents and heat stopped working so I am wondering if it could just be a fuse(s) and not the motors themselves since they have not likely been worn out based on use. Anyone happen to know, before I try to dismantle the dash... again?

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KrazyKyle
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Re: Fixing no heat issue is Z32

Postby KrazyKyle » Tue Aug 24, 2021 5:56 pm

AZ300Z wrote:
Tue Aug 24, 2021 5:09 pm
Great post! I am pretty sure my car has the same problem (a/c and auto cc works, but no heat or vent control) but mine is a low mileage (27k) 1990 and at some point without much use, the vents and heat stopped working so I am wondering if it could just be a fuse(s) and not the motors themselves since they have not likely been worn out based on use. Anyone happen to know, before I try to dismantle the dash... again?
I would think that the rest of the climate control would stop working if it was a fuse. It could be a ground or connection somewhere though. The one thing I noticed when I disassembled the motors I had, was that the lithium grease had almost solidified. Being that low of miles at that year without being driven can cause problems just like a high mileage vehicle. Most of the electrical can be investigated without taking the dash out. Check the FSM out and it will help you out.


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