1990 240sx Heater Control problem

[lbrowne]

I have the push button heater control, but I do not have an AC equipped car.

If I push the button for any directional setting (defrost, floor, etc) it doesn't change from where it currently is blowing air. Sometimes it will slooooowly change over but for the most part it doesn't at all. Sometimes shutting off the heater and then turning it back on makes it go to where you've selected.

Its almost like the vent inside is sticking or something? I found this link:

zerothread?id=45262

Anyone else have this prob? Or know what it could be from personal experience? The blower motor is fine, all the speed settings work. Just the directional seems to be not functioning properly if not at all.

[JeromeS13]

Yes. As NISTECH mentioned, it is the mode door motor (located just above and inboard of the gas pedal). Give it a tap while changing selections. If it doesn't move, you probably need to replace it. Otherwise, there is a step by step troubleshooting section in the FSM. It walks you through checking the control unit and the motor.

[lbrowne]

Tap the panelling there? Or take it off and tap whatever apparatus is there....

Just wondering if this is something I can try out as I'm on my way to work tomorrow.

[JeromeS13]

There shouldn't be anything covering it. You should see a motor and some links on it.

[lbrowne]

well I went out to the car this morning and started her up. clicked the buttong a few times while tapping the unit - no dice.

Without touching it and just listening to it you can hear it ever so slightly trying to change direction of the airflow if you listen to the airflow. So it tries, it just doesn't get too far in the process.

It was far too dark for me to look at anything since its black out when I leave for work anyways.

[lbrowne]

Well I got underneath with one arm out and around today. It was moving a bit but almost like from sitting so long not touched by the previous owner - its just ceased up a bit. If I helped it allong with a tap of my finger it would finish the directional airflow change.

I got it pointing on the windshield now. Thanks for the help guys. (maybe just a little bit of grease to spray on it to help free it up more?

[dougw714]

I have a 90 pignose with a similiar problem. Mine car has ac but recently the compressor seized and the belt broke and i have been unable to change the vent direction(guess you can say i dont have ac anymore). The fuse (third down on the left) shorts out as soon as i switch the motor on the slowest setting. The blower still works but i cannot change direction of the vents unless i turn it off, put a new fuse in then change direction of the vent(the lights will come back on the dir buttons). I can hear the motor moving but the fuse blows as soon as its turned on.