82 380sl with solenoid heater valve.
any way of testing this valve to see if it works
put a new replacement mon valve replacement in the valve but it still blows hot air all the time.
put 12 v on contacts and they did click but nothing appeared to move.
should you be able to see the valve move up and down from the top of the valve( the round cylinder on top of the valve)?

No, you can not see anything.

The valve always has power to it and is "on" when there is no ground on the other pin to close the circuit. When "on" water flows. When the ground side is engaged by normal control or by jumper there should be no wster flow.

The only easy way to tell if the valve works is to see what happens to the duct temperature. Squeeze off the flow with some vice grips to verify that it will cool down.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

should there be a voltage across the electrical connector when removed from the valve with the car on, off ,heater on,heater off?
should you vise grip the top hose or the bottom hose?

The valve is held closed with battery voltage. It does this for sure only in the "Min" position of temp control. In this case if one put a volt meter across the two terminals, while in one's hand (not connected to nothing), one would get battery voltage (or close).

In any position but min the ground is applied in a pulsed fashion! Off..on..off..on..etc. depending on the temp decision. Using a graphing multimeter (GMM) it looks like a square wave of varying duty cycle and frequency.

Grab the hose either side in a convenient spot. Take a section of old hose and cut it such that it can be placed under the vicegrips so the visegrips don't hurt the installed hose. Don't squeeze at bends, squeeze in the middle of the most convenient long straight section.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

i still don't know which hoe to clamp top hose or bottom hose coming of engine?
clamped both separately and neither stopped the hot air from coming in in the most cold position
is the climate control unit bad?
the temp wheel bad?
the heater control unit under the passenger floor?
the heater valve bad?
can't get this warm air off me when driving and tepm wheel at full cold and blower & climate control unit on off

help its hot drive with the top down and heat blowing at you