Cooling Fans Continuously Run On Ae93 7afe

[rob83ke70]

cooling fan problem:

after removing the control relay and inspecting the control side of the circuit to find that it is working correctly, I tested the relay, found it was working correctly, and then re installed the relay, and now my fans are working correctly.

 

conclusion: the relay was jammed in position completing the supply (controlled) circuit and when I "tested" it by actuating the control circuit several times and measuring the resistance of the supply (controlled) circuit, I must have freed it up.

 

there are only two things that affect the control circuit for the cooling fan, the temperature switch (single wire on thermostat housing) and the a/c pressure switch. the switches are normally earthed, powering the control circuit which pulls the controlled circuit open, and when temperature or pressure is reached, the switch becomes open circuit, which then allows the normally closed cooling fan relay to power the controlled circuit and activate the cooling fans. should there be a break in a wire of the control circuit the fans will come on.

 

I hope that makes sense.... much nicer to explain with a wiring diagram!!

 

I have fault read it again as well, and the only code present is the knock sensor code.

 

Robert.

[rob83ke70]

knock sensor replaced, no more codes present, everything working as it should.