HVAC module Part Deux

[slepec]

Hello again.

Before I dismantle the HVAC completely, I really need some additional info.

Here is my problem: in my 94 TS ventilation is only working through door AND (not OR) defrost, no matter what I press on the A/C control.
Now, I tried to narrow the problem, and after some careful listening I noticed that when I press RECIR (which engages A/C) I could hear one of the hatches going up (or down, it doesn't matter).
I reckon that if it is something wrong with the vacuum, NONE of the hatches would work because, as I can see, there is only one intake vacuum hose for all the valves, right?
Now, could it be that 4 of 5 valves are faulty since all the hatches but A/C seem to be dead? How could I tell for sure? Does it make sense to try and self-repair/replace?
If it's not the valves, could it be the solenoids that control opening of the valves? Is it hard to replace (maybe even repair) a solenoid since I'm not exactly a fan of electricity?
And one that's really puzzling me: is it really necessary to drain the coolant before dismantling the HVAC?

Or am I completely wrong and I should go and study hydroponics instead and leave deducting to more intelligent people?

Or should I drive the car down to the mechanic and beg him nicely to have mercy on my wallet?

Replys are most welcome.

[knuckle ears]

Originally Posted by slepec

Hello again.

Before I dismantle the HVAC completely, I really need some additional info.

Here is my problem: in my 94 TS ventilation is only working through door AND (not OR) defrost, no matter what I press on the A/C control.
Now, I tried to narrow the problem, and after some careful listening I noticed that when I press RECIR (which engages A/C) I could hear one of the hatches going up (or down, it doesn't matter).
I reckon that if it is something wrong with the vacuum, NONE of the hatches would work because, as I can see, there is only one intake vacuum hose for all the valves, right?
Now, could it be that 4 of 5 valves are faulty since all the hatches but A/C seem to be dead? How could I tell for sure? Does it make sense to try and self-repair/replace?
If it's not the valves, could it be the solenoids that control opening of the valves? Is it hard to replace (maybe even repair) a solenoid since I'm not exactly a fan of electricity?
And one that's really puzzling me: is it really necessary to drain the coolant before dismantling the HVAC?

Or am I completely wrong and I should go and study hydroponics instead and leave deducting to more intelligent people?

Or should I drive the car down to the mechanic and beg him nicely to have mercy on my wallet?

Replys are most welcome.

First thing, if you haven't done aready, check all your fuses.

Second, go to the auto wrecker and pick up the heater a/c control module( the control with all the buttons on it. "lower , defrost, a/c, etc). Take the whole thing.
Also pick up the solenoid valve that controls the damper motors- the one you mention above.

It is well worth trying to repair yourself. I had simialr problems and these solved everything. Going to a mechanic would prove expensive.

[slepec]

Thanks, knuckle ears.

Yes, the valve that controls the damper motors... I hope it really will be that easy. Thanks for sharing your experience. I have to go scavenging now...