Radiator fan wont turn off after new thermostat sensor??

[rumpelstiltskin]

MY RADIATOR FAN WASN'T SWITCHING ON UNTIL AFTER THE SECOND LAST POINT ON THE GAUGE WHICH WAS MAKING ME FEEL A BIT UNEASY.i INSTALLED A LOWER TEMP SENSOR IN THE RADIATOR AND NOW THE fan (which incidentally comes on same temp as last one??)won't switch off lol,can't believe it!Can the new switch be faulty,i thought maybe i had the two wires on the wrong way round,but don't know if this would affect anything?

[jamie_clioGTT]

the two wires shouldnt matter which way, its just a switch so perm live and a switched live. did the fan turn off before?

are you sure its getting cool enough for the fan to turn off?

[rumpelstiltskin]

Yes the fan switched off before,it's weird.I was a bit miffed the fan didn't kick in earlier than my last thermostat switch,then when fan didn't turn off i thought it must be a faulty new switch??I actually gave it a good five minutes with the fan stuck on and the car switched off so engine/switch should have been cool enough then to switch off fan?.(temp gauge was down to first mark)

[SCHWARTZ]

fan coming on on the second line sounds about right to me. put the old temp switch back in and make sure you get all the air out the system.

[rumpelstiltskin]

Sorry,didnt word that right,i meant i hung on until the temp went down to the second mark,and the fan 'still' wasn't switching off?The fan wasn't kicking in until after the third mark??Even with this new lower temp sensor switch!

[Kris M]

rad fan relay

[rumpelstiltskin]

Ok,bit of progress.Replaced radiator relay with other one i had lying around,now the fan is turning on and going off like it should.Thing i don't get is the fan is taking an eternity to come on!!It comes on between the last two marks and in fact sometimes i panic and switch it off and blow a fan i have on the engine!!Few minutes after switching it off the fan comes on lol.New switch i got is rated at 77/67 degrees centigrade so it should come on kind of early?All air is bled out the sytem incindentally.

[Kris M]

Dont rely on the standard gauge for your readings tbh. They all tend to differ slightly from experience. If your worried, take a temp reading with a probe type thermometer between the fins of the rad, that will be more precise :)

[Brigsy]

77/67 is far too low for rad fan switch, the rad fan wont turn off as the rad fan wont be able to cool it down to those temps...above the 2/3 line is fine, dont panic these engines dont suddenly go bang when over the 2/3 mark lol

[Slammed 66]

Purely out of interest, did you buy your low temp switch from CGB?

I bought one from them and it also seems no lower than standard.

Ross