I have a 2008 S250 I've had for a few years. The fan switch never worked but recently decided to try and diagnose the issue. The switch itself doesn't get power. The fuse is good. I found a relay under the cab that looks like it runs up to the blower. It has 1 red wire 1 black wire and 2 orange wires. If I jump the orange wires together the fan kicks on and switch operates as it should. I replaced the relay with a new one and still doesnt work. Is there a inline fuse or gound that may be open? Whats the wiring diagram look like for this circuit?
