lbs_ft

Hey guys, here's my problem: up until this morning, everything regarding my climate controls worked fine. Car is a 1990 240SX and I have the factory analog controls. The blower vents seem to be stuck in the defrost mode.

I can still control the fan speed and the temperature, and all the lights work on the controls. When I push the individual buttons to select the mode, they light up according to which one is depressed and which mode it should be in, which tells me I have power. But no matter what, no response, still stuck in defrost.

I've never had any problems from it until now, does anybody have any ideas?

SortaFlush

Defrost is usually a "fail safe" mode when there is a problem with HVAC in a vehicle. I haven't been into the dash yet, but I do believe that these are vacuum controlled diaphragms and you might have a problem with one (could be a simple rotted vac line on a 20+ year old car).

lbs_ft

I ran through all the stupid troubleshooting guides in the FSM, and after I came to the conclusion that everything was hooked up and getting power, I assumed it was the motor. It's just to the right of your right knee when you're sitting in the driver's seat, so I jiggled it and tried switching the modes and it worked just fine. I guess the motor was just clogged up or something

JDM180SX

no vaccum controlled setups on the 240. i yanked all my stuff out and there were no vacuum lines. The climate control will need to be replaced.

That is the default setting for when it goes out. Nissan designed it that way. It will need to be replaced if it is not a wiring issue.

JDM180SX

sorry did not see you posted...glad you got it fixed!

lbs_ft

hell yeah, me too haha it will need to be replaced eventually though. Not only is the mode motor sticky I guess, but the fan is pretty loud when on 2 or higher speed. It rattles and seems very unhappy. I'll replace them both if I ever have to get inside the dash

JDM180SX

Its easy...you need to remove the long cable wire first ( hooked to the blend door ) which you can see looking up under glovebox. remove 4 screws and unplug it and your done. i had like 3 mint units, but i sold them on ebay over the summer.

buentellomma

Had the same issue a while back..... What the heck is up with my blower making noise? Sounds like its full of leafs or something when it running

JDM180SX

thats prob what is. they get under the plastic cowl and fall into the opening where it draws in air.