Where is the auxiliary fan switch on an 03 ex and how would I go about testing it to see if it's still good. Secondly where is the thermostate and how would I go about testing it....
Before I answer...a few other things to ponder:
Did you check fuse #4 (20Amp) in the underhood box, and #14 (10amp) under dash?
When/if you need it...The radiator fan relay is in the under hood fuse box (lower right side as you're looking down on it.) It is a "normally open" relay.
Does fan work with A/C on or not at all?
Cool....now some info:
The fan switch is at the bottom of the radiator....on the fan side, just about in the center. A "quickie" way to test it "jump" the wires at the connector going to it and see if that makes the fan run. If the fans start working it is prolly the switch. :wink: The "right" way is to pull the switch and put it (suspend w/ terminal side up) in a container of hot water. Check for continuity accross the two terminals...there should be contanuity around 195-205 deg F. It should switch "off" (no continuity) about 5-15deg F less than the "on" temperature.
A quickie way to see if the fan motors work is to just take power direct from the battery to the (disconected) fan wires.
The thermostat is at the motor end of the lower radiator hose. Pull the hose off and pop it out of its special little "housing." Put it in a container of water on the stove...it should start to open around 170degs. By 190-195deg it should be fully open. (sorry, I don't speak Canuck, so maybe someone can translate my temperature descriptions into centergrade :wink
Good luck, have fun.