Air Conditioner Not Blowing Cool

[newlexman]

HELLO EVERYONE.

I have a 91 ls400 and the air does not blow cool. I havent had the car officially checked by expert but my mechanic friend says it has 40 lbs of coolant and all systems engage fine when it is turned on. Could anyone tell me some things to check to repair this. Blower works, heat works fine, it just doesnt cool.

[wwest]

HELLO EVERYONE.

I have a 91 ls400 and the air does not blow cool. I havent had the car officially checked by expert but my mechanic friend says it has 40 lbs of coolant and all systems engage fine when it is turned on. Could anyone tell me some things to check to repair this. Blower works, heat works fine, it just doesnt cool.

In the engine compartment at the top center of the firewall is a coolant flow (to the heater core) control valve. As you change the demand from maximum heat to maximum cooling the cable driving that valve should move it from fully open to fully closed. If the cable is not attached the valve may be stuck in the open position. If the cable doesn't move it may be disconnected from the blend door servomotor inside the car, near the climate control air distribution plenum.

Bottom line is it appears that the blend door servomotor has gone south.

Or the coolant flow valve is so "gunked" up (typical!) the servomotor can't move the valve or the blend door.

In that case slip the cable off of the valve and see if the servomotor can drive the blend door alone.