the passenger side cooling fan kicks on and off with the key on, engine cool, at about five second intervals, there is a relay that sounds like a hazard flashing that is clicking, any ideas?

Diagnostic plugs are plugged together.

yep, you got it bratman!!! my passenger side fan would run every five seconds with key on regardless of engine temp, I connected a plug in underneath the dash above the left knee yesterday as I was underneath doing some other minor wiring, two parts of a connector were staring at each other but unplugged, well plugging them together causes that fan to run when the key is on, unplugged, back to normal fan operation. What is the purpose of plugging them together?

they are for diagnostic purposes. there are actually 2 pairs, one green pair and one black pair.

 

What year is your car?

the Forester is a 98 5 speed dohc, I think they were green

They're diagnostic connectors. It puts the ECU in test mode which cycles all of the relays and solenoids in the car.

it will also throw a boat load of CEL codes.

 

does the AC work?

one of the fans comes on with the AC.

if the AC is cycling due to low refrigerant, the fan will as well.

Edited March 28, 201412 yr by johnceggleston