bad heater control valve?

[Daeldalus]

when you have the heater control valve out of the car and unplugged. Is it supposed to be open or closed?

I cracked the heater core in my m52 swap car and as i was pulling out the old one I noticed that the heater control valve was not even plugged in. I have been getting great heat and was able to bleed the system(though it took a few tries).

so I decided to try to blow through the valve to see if it was closed. I was able to blow through it both ways with zero resistance. Is the valve normally open? like does it open when it is unplugged? or is it normally closed, which means I am screwed?

[reelizmpro]

Edit: seems I had it backwards. It is normally OPEN without voltage and closes when voltage is applied.

From the ETM:

When the solenoid is energized, coolant flow is shut off to allow maximum cooling from the a/c system.

[iPee]

It is normally open when unplugged, no voltage. When voltage is applied(air temp dial cold) the valve will shut.

[Daeldalus]

OK now I am confused.

I might just have to put some power to it to check.
Will that mess up the valve? Putting just straight power to it.

[Das Delfin]

if you get heat, that means the valve is open. If you can blow through it, that means the valve is open. If both these happen with the valve not plugged in, logic would dictate that the valve is open unless voltage is applied

[Daeldalus]

Well, the people that had this car before me were not the smartest when it came to cars. they had a bunch of stuff screwed up before i got the car. I was thinking that they might have destroyed the rubber diaphragm somehow which would have made the valve open all the time.

[Daeldalus]

Bonus questions

where is the fuse for the heater valve located?
what colors are the wires to the valve supposed to be?

[Daeldalus]

definitely never ever test one of these valves while it is out of the car!

I burnt mine up doing that and had to spend an hour under the dash of nasty car to get another one. and it does work.

[iPee]

If the diaphragm is destroyed it probably won't seal as well. I'm in the process of replacing my heater valve as well, bit the bullet and bought a new one.

[reelizmpro]

The fuse should be in the same area on the side of the box. It's small and tucked in there so you'll have to look for it.

[Das Delfin]

check this out

http://www.e30zone.net/e30zonewiki/images/3/3d/E30_heating.PDF