Fan switch causes temp guage to go haywire....

[WA-EG]

Ok so I was out driving yesterday. I was heading up into the hills at around 100kph with the air con going. noticed about half way up the hill temp guage was sitting just just under H.

Had a mild shit attack and pulled over to side of road. waited for a little until i could get the radiator cap off to check if water levels had dropped. all good. checked oil, still good colour and still there. :-S

decided to get back in car and start her up again. waited for bit with it just idling. temp got to normal spot and stopped. so off i toddled down the road again. as it was like 40 degrees wanted to put air con on. noticed when i flicked the fan on the temp guage jumped up higher with each faster fan speed......?????

the annoying thing, when i drove the car later the same arvo in same conditions nothing happened. so it got me stumped.

Help........
Apologies for the novel.

[VT3C]

got the exact same problem in my GF's Prelude at the moment.. I think it's the A/C pushing it over the limit - turned off the AC and it went straight back to normal in like 1 minute... but what's the point of Air con if u cant use it on a hot day ??

Also has developed the standatd honda erratic idle also since then and I suspect both may be caused simply by air bubles in the coolant ? but I havnt done any further investigation as yet... not quite sure why your fan speed would have anything to do with it though.. but it does seem to increase the load on the engine as you turn the speed up.. ??

this is why i ripped a/c out of my EG lol..

[WA-EG]

yeah does seem like its overloading the system but i wouldn't think that would be the case.

Surely the car can handle the aircon system being on on a hot day???? i was sitting listening to the idle the other day. does sound like the idle drops a fair bit when the fan gets turned on.