i can't see how but a (mechanic) at the bar,says that because my o2 isn't hooked up my fan won't turn on. i just can't see how they are related. but at this point im open to suggestins on how to get my fan to turn on. if i jump relay it turns right on. if i short the fan sensor in the pass. side head it turns right on .just won't turn on by itself.????

 

What makes you think it "won't turn on"?

You realize that the factory set point for turn-on is about 235°, right? Have you verified that it doesn't turn on when the engine reaches that temp?

 

how can i verify the temp? it runs for a long time ,and doesn't come on.

 

you could use a Sears digital multimeter. They have several models. The one for $40 and other for $50 both look pretty awesome, will pick one up sometime. Anyway, they can be outfitted with temperature sensors. you would just touch the temp probe on the block near your car's temp sensor and that'd give you a good idea of how hot the engine was.

 

thanks guy i will check into one.