560sl heater problems

[mreddy]

89 560sl, heater only works minimally when in the auto position, when the fan is turned to on it blows cold. blows just barely warm in the auto positin. Any ideas. also, the air recirc swithc will not stay on form more than a few seconds.

[david s poole]

pull the mono valve element and see if the area below the diaphram is full of coolant.check that you have an unbroken circuit thru the outer windings.that valve needs voltage to stay closed[every time you switch off car valve opens] so the last thing may be the push buttons.