My cruiser overheats.last week I had a code of p 309....if I am right....number 4 cylinder misfire.. that went away....we thought it was moisture.on the wires..yesterday it overheated while idling, the temp lite came on gauge pegged.......drove it home 2 miles..as soon as clear traffic it cooled down.replace slow and fast relays for the fan...isolated the harness that goes to fan, shot 12 volts to it...fan runs great. reconnect it after new relays..idle it overheated...fan will not cycle. Jumped around temp switch..the one in the t-stat houseing and now check engine lite and gage are showing oveheat even with engine cold. why doesnt the fan cycle? is there another cooling swich that I am missing? Thanks..........