Fan is not coming on

[courtenay]

My fan doesn't seem to want to come on by itself. Jim Ellis (PO) put a bypass switch in and it works, so I know the fan is OK, and I presume the fuse as well. The temp almost made it all the way into the red today (at idle) and no fan.
What should I look at next?

[swede]

temperature switch in the radiator migth be broken

[narfire]

Bruce, I trust all the wires are connected/clean. I likely have a sensor from a spare rad here.
Do you have the wiring diagram from Brad Artique?

[courtenay]

I've checked the wiring diagram and I think I've traced the thing through and ensured all the connections are clean. As far as I can tell, on the fan itself, the only connection is the one near the fan itself. Since the fan does turn on with the override switch, I'm assuming the fan circuit is OK.
One thing that did happen is that when I changed my timing belt, I hooked the wires up wrong - I hooked the wires from the fuse block that were supposed to go to the fan into the sensor and the sensor wires to the fan. The result was a blown fuse for the fan and horn. Since there is nothing protecting the sensor, could connecting it the way I did have fried the sensor before the fuse blew?

[NebraskaSpider]

Do you have a burp valve in it? You may have air bubbles in the cooling system.

[ITA124]

Short the terminals of the temp switch with a wire or paperclip. If the fan turns on, its your temp switch. If it doesn't, then there is no power to the fan.

[courtenay]

Paul - the fan is working - I've got a bypass switch that essentially does what you're suggesting and the fan comes on.
I also burped the system - I've got the Prestone flush kit. The bottom rad hose and the bottom of the rad are as warm as the top so there is definetly circulation.
I guess it's the sensor.

[Fiat88]

If you need a fan switch, I have an extra one you can have.

[narfire]

If I'm near the shop tomorow I'll pull one from my spare rad and send it up.

[courtenay]

Thanks Fiat88 - Chris (Narfire) is a lot closer. Chris - really appreciate it!
Bruce

[So Cal Mark]

sounds like a bad switch