Hi,

I just bought a 96 300zx convertible. I am in the process of fixing the many little things wrong with it. One of the things wrong is when using the selector to move from vent to defrost to floor it does not work. I get a constant clicking sound when attempting to select a new position. If I leave it on face vent everything is cool. But it would be nice to have defrost to clear the windshield from fogging. This has prevented me from driving my car in the mornings to work.

I understand it is either the vent or the motor assembly. What I would like to know is if can be fixed without removing the dash. I have read everything I can on the subject and I can't seem to get a good solid answer.


thanks

Also mine is the manual type climate control.

I had some time last night to take a look up under the driver side dash. After removing the panel under the steering wheel and about 4 vent piece extensions I was able to remove the vent control actuator. It wasn't as bad as I thought. Maybe an hour. When I install it I think I will remove the driver seat to avoid twisting my body in ways that it doesn't want to bend.

Also Looking on Ebay I believe that a 1993-1998 Quest actuator will work. It looks exactly the same but the control arm is different. I should be able to slide my arm off and install it on the new actuator. Also maybe the mercury villager may be the same as well. It is a rebadged quest. I post this info incase someone needs one and has a pull a part around.

I also figured out why my actuator went bad. When a past owner had a viper alarm installed they ran a few wires thru the vent causing the next vent piece not to properly seat on the first piece. Therefore the second piece came to rest on the door linkage. This caused a bind which caused my clicking. It would click all the time until the other day when the clicking stopped when the motor burnt out. I thought I smelled something...

I recently had to change out the mode door motor on my 93 NA 2+2... Same basic thing. Yes, you should totally remove the drivers seat, it's only 4 bolts and an electrical connector to deal with, and you get to clean under it as a bonus

My climate control is automatic, so I also had to remove and replace that AC Amp with it's 4 electrical connectors (what a PAIN... literally) I'm very happy I did it, I just hope I got all the piping back in place correctly.

So last night I got to fool around with this actuator. After taking the seat out the job is more comfortable. But... I am having a hard time. What I am currently doing is with the actuator arm off and attached to the linkage attempting to keep everything aligned and push the arm onto the splined shaft of the motor. This is not working. I am going to have to think of a new method. Getting the motor off and out was a whole lot easier than getting everything lined back up.


BTW. I was able to repair my actuator. The actuator contains a small motor with a worm gear. The gear box contains 4 plastic gears. Two of these gears rotate on a plastic pin that is molded into the housing and there is another pin that another gear rides on. The pin that holds the two gears broke causing the gears to float and not make good contact with the gear that drives the arm. What I did is create a small hole in the top cover and drive a #6 screw through the top cover to give the gears something to rotate on. it works pretty good. Word to the wise. Save yourself a lot of headache and do not take the arm off the splined shaft like I did. If I hadn't the actuator would have "self homed" when plugged in with the heater on. then all I would have had to do was hook it up.

Also ever if your motor burns out I think it wouldn't be bad to get another motor the same diameter and replace it.

Not to thread jack but will the replacement of this motor correct the clicking sound you were describing? I have a similar issue with my 90. Vents dont change position, and I sometimes get a clicking when running the a/c, sounded like it was coming from the glove box area though.

The clicking was because the gears not meshing correctly causing them to click as the teeth rode over each other. And this is caused by a bind somewhere in the door linkage or the gears wearing out. The bad news is that that motor on that side can't be replaced without removing the dash and the heater core from what I have been reading. But you can slip under there and see if that door is in a bind or not. Maybe spray it down with a lube.

The vent side that I am talking about has nothing to do with that other motor. They do two different things. But if you repair the driver's side one you will have vent control again.

And one other thing. Before you attempt moving the flappers you should disconnect the door from the actuator. Otherwise the actuator may get damaged.

I have other information to add incase anyone else needs to fix this actuator on their car later.

Fixing the actuator is a piece of cake once I figured it out. At first I ran a screw (#6) through the top of the cover. But having some flex caused the gears to become disengaged making it very weak. Therefore I ran a drywall screw completely through the case and cover and cut it off where it exited through the bottom. Just be careful you center the screw where the shaft used to be attached to the housing. this will allow the gears to mesh correctly and prevent you from hitting metal traces on the housing.

So to recap.

1. Take the actuator out of the car.
2. Break off the 4 tabs and open the gearbox top cover. You won't need these anymore.
3. Use a pocket knife to create a hole in the top cover where the boss is.
4. Take the gears out and make a hole in the bottom housing where the shaft was once attached. Make sure to get it on center.
5. Install the gears and put the top cover on. It works better if you install the screw part of the way down to slip into the gears as you slip the cover into position.
6. Completely run the screw through the top and the housing.
7. Trim off the excess of the drywall screw with side covers that is sticking out.
8. Before reinstalling make sure your linkage moves freely.

Now you will have a actuator that is stronger than the factory. Keep the $76 or more that they want for a new one and use it for something else. Beer?



Also if you remove the arm that isn't a big deal either. The motor will self home when hooked up to the connector and turned on. I turned the selector completely counterclockwise. Then installed the arm on the actuator and adjusted the linkage until everything operated correctly. If you did it correctly there will be no noise at the defrost setting. Or just save some time and don't remove the damn arm.