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Newby: Heater blowing cold air...

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I have been looking through other threads on here, but I am unable to wrap my brain around this (probably simple) problem.

My 1983 528e heater blows cold. The fan works fine, and the coolant temperature warms up past the "blue" area on the gauge. But still cold air.

I read about the heater valve (I hope that is the right part name... it is on the firewall below the brake booster) and thought that might be the problem. If I understood right, unplugging the wire on that should make it default to "stuck on hot". I tried this and it still blows cold...

Am I correct on my understanding that removing the wire would make it blow hot???

Any suggestions on a next step?

At this moment, I am OK with a temporary fix that makes it stuck blowing hot.

Cervantes (who just ordered a Bentley Manual, having found the Haynes manual less than helpful.)
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Yes the haynes sucks. As to the heater valve it can brake 3 ways

1 blows only cold
2 blows cold only when driving on the freeway
3 blows cold all of the time.

Go to and order the rebuild kit to replace the valve. It is about 65 dollars.. just take off the top four screws pull out the valve and stick in new. Put screws back. You now have heat.

Well if it turns out to be as simple as that, I should be in luck.

Is there any way to test it to very that this is the problem before ordering the kit? Is there a wire you can jump or something like that that could verify the problem is the heater valve? I can't afford to buy too many parts if they don't fix the problem, if that makes sense.

Pull the part and see if the rubber gasket is shot, if it is then that is the problem. Also that is really the only problem it can be, the heating system is very easy.

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