OK changed the the hose's,thermostat, switch at the thermostat,bled the system,radiator is 1 yr old. Overheats when A/c is on, jumped the the switch, fan stay;s on all is good. WTH is with this pig I reconnect the fan switch to the thermostat plug and the fan will not come on.Top hoes is hot bottom hose is hot the water is circulating but no fan Grrrrrrrrrr

 

Air bled out of the system? Raise front of the vehicle, turn heat on full hot, and run car for awhile with no radiator cap. This will allow the air to bled out of the system. That could be your problem.

 

Bad fan switch?

 

i think ive posted this vid three times in the past week.

 

Yes I have done this this civic actually has a air bleed valve in front of the manifold.Did elevate the front end and ran with heat on HI HOT.by fan switch if you mean coolant temp switch located by the thermostst that has been changed twice. Both top and bottom hoses get hot so thermostat is opening.I can jump the switch and fan will run constantaly as it is now.

 

Does the engine still overheat if you drive with the switch jumped and fan running constantly?

When you pushed wires into the switch plug to jump it, you may have damaged the contacts so now it doesn't make contact when plugged into the switch. Even though the switch is good, the fan wouldn't come on then.

 

No run's normal on the highway and in traffic. I'm entertaining the thought that it may be a computer communication problem,but i would think that that would throw a code and of course it doesn't. But thank-you any idea's are good idea's.I also replaced the fan relay yesterday but no luck

 

ItBurns,
Thank's for the video but have seen this and Eric several times,but Thank's for the input

 

There is no computer involved in controlling the fan. Just the thermo switch and the relay.

 

Well thanks for popping my bubble. Now i have to think of something else