LiL JoN

just picked a 99 civic but the cooling fan dosent turn on checked the fan direct to the battery and it does work what could it be HELP.........

THANKS

Former User

It's likely either a bad fan relay or a bad coolant temperature switch in the thermostat housing.

Disconnect the connector of the coolant temperature switch and insert a jumper wire into the connector on the wire harness side. If the fan turns ON, then the switch is bad. If it doesn't, then the relay is bad.

ELE0MENT

I also have a 99 civic Si and am having problems with the cooling fan. Ive checked the relay and I have also changed the cooling fan switch and still nothing. The fan will kick on but not when it is supposed to. the engine never over heats. Once I start moving the temp gauge goes to the normal operating setting. But when I sit at lights and what not the gauge starts to climb. usually the light will turn green b4 it gets to where I get worried. BUt this fan is getting annoying. Any suggestions? Anyone from the upstate Ny area?

Mashimaro

iTrader: (1)

check your fuses. i suspect the one for your fan is blown.

ELE0MENT

Ive checked all the fuses. They are all good. Ive changed the cooling fan switch as well as the coolant temp sensor. Ive pulled the relay and jumped it with tweezers and the fan kicks right on. Ive also pulled the connector pin from the cooling fan switch located on the back of the thermostat housing and test lighted that. The the test light did not come on when I tested that connecter, so does that typically get juice? Or does it sound like a bad wire or connection?

ahobbs

get a new relay

ELE0MENT

I can tell you now that the relay is not shot. the a/c condensor fan relay and the radiator fan relay are the same type of relay. I had swapped them to check if it w as a bad relay and that wasnt the case

ahobbs

new thermostat switch

ELE0MENT

done it already