1990 240SX heater controls problem

[++Tripps++]

I have a 1990 240SX and the heater controls no longer change the vents from the dash, to the defrost or the floor positions.

The fan and heat work fine, just no vent switching.

This summer my AC Compressor was locking and I removed the belt (need to replace the comp), and I thought this may have had something to do with it but I can't find any blown fuses or unplugged harness in the dash or out under the hood.

Any Ideas? I live in New England and need a defroster - bad!!!

Thanks in advance.

[NISTECH]

you need to check the mode door under the dash is it auto air or manual air?

[++Tripps++]

It's a 5-speed if that's what you mean by auto or manual air.

Is there some sort of vacuum or electric solenoid that throws the mode door? It never gave me any trouble before, it just stopped working altogether one day for no apparent reason.

I'll look under the dash in the morning and get back to you.

thanks.

[NISTECH]

no I mean is it auto a/c or manual a/c controls. is it a push button system or do you have a display screen that shows the temp and you adjust it. if its manual you have cables that control door operation.If its auto your have electirc or vaccum controlled mode doors.

[++Tripps++]

Oh I see... It's push button but I don't think the buttons actually are connected to a cable, just switches of some sort.

[NISTECH]

yea its an actuator. either vaccum controled or electrically controlled. look up under the dash near the heater box while pushing the selector buttons and watch for lever movement. if its vaccum controlled you probably have a leak in the actuaator diaphram. if its electric the motor in the actuator is pobably open. if you can locate the right one you can usually tap it while making selections and it will move and may work again for some time till it stops on the open circuit part again.

[++Tripps++]

Thanks, I'll give it a shot and let you know how I make out with it.

Hopefully it will switch modes, We're getting dumped on with snow again