badaca Posted June 16, 2008 Share Posted June 16, 2008 looking for help. My car overheats with a/c on. the engine fan does not spin fast (high speed) when the a/c is on i was told their is a switch on the power steering pump to allow more flow to the fan when the a/c is on. can anybody help with this problem? Quote Link to comment Share on other sites More sharing options...
LoveLearn Posted June 17, 2008 Share Posted June 17, 2008 "engine fan does not spin fast (high speed) when the a/c is on" First check your power steering fluid level. I've seen another 1992 ES-300 overheat from insufficient power steering fluid which as you know also spins the radiator fan's hydraulic motor. If fluid level or pump-drive-belt slipping that isn't causing these symptoms, I'll look in our 1992 ES-300 Factory Service Manual. When their power steering rack starts dripping fluid, eventually power steering fluid level will drop low enough to cause overheating by way of insufficient fan speed. These cars abound with tricky symptom trains like slipping crankshaft pulley outer section noticeable only by charging system warning light flickering on often by not spinning the belt driving the alternator sufficiently fast. John Quote Link to comment Share on other sites More sharing options...
byf43 Posted June 19, 2008 Share Posted June 19, 2008 looking for help. My car overheats with a/c on. the engine fan does not spin fast (high speed) when the a/c is on i was told their is a switch on the power steering pump to allow more flow to the fan when the a/c is on. can anybody help with this problem? Check the A/C 'cycling' switch. This switch is supposed to cause the solenoid to open and allow full pressure from the PS pump to the radiator fan motor, to create maximum fan rpm. There is a test in the manual that can be performed to check the condition (working or not) of the 'cycling' switch. Quote Link to comment Share on other sites More sharing options...
CUMan Posted June 20, 2008 Share Posted June 20, 2008 I would suggest that you check the power steering pump and make certain that the wiring harness which connects the fan control computer (under the dash) with the power steering pump is plugged into the pump. This connection is often unplugged when engine work is done and seems to be left disconnected a lot. This connector is critical for proper fan operation. If the power steering pump does not receive the proper signal from the fan control computer, the fan will not operate with enough speed to keep the coolant from overheating. Such overheating usually occurs when the engine is idling or when the car is not moving very fast. At highway speed, there is enough air flow to keep the coolant in a safe range. At slower speeds or when idling, the proper fan speed is critical to keep the coolant temperature down. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.