Heater on All The Time

[YoRam]

Hey guys, I have a problem where the heater is on all the time. Any ideas? PS, 535I 1985 Stick.

[Shawn D.]

Make sure the valve is getting power. No power = full open.

[stuartinmn]

The heater valve normally fails so you don't get heat, but it can fail the other way - it happened to me once, and I was getting full heat all the time. A replacement valve solved the problem. There should be a writeup in the tech FAQ section about replacing or repairing it.

edit: here's the writeup. http://www.mye28.com/viewtopic.php?t=17342

[YoRam]

Thanks, I do get power at the valve after the motor warms up, is that how it should be? I will take the valve a part, will farther inspect and post the results.

[Shawn D.]

Thanks, I do get power at the valve after the motor warms up, is that how it should be?

Power should be at the valve any time there is no call for heat -- it has nothing to do with engine temperature.

[YoRam]

I have exact same problem, and waiting for replacement valve. DO THIS: 1. Unplug the wires from the Valve Solenoid 2. Ignition On, Temp knob on Cold, Check for Voltage > If no Voltage present Check why, If Voltage present > Measure for 15.5 Ohm resistance across the valve solenoid contacts. If you get reading > Open the valve by removing the 4 screws on top of the valve and check that the diaphragm and all the rubber inside is in good condition. If there is No Resistance reading, Get a New or Used complete Heater Valve. PS 85-535i

[YoRam]

Correction!! Resistance Should be around 11.5 Ohm