Ford Sierra Efi Dohc Engine Running Temp

[steve in stockport]

So you have the original fan switch and an after market switch. Chances are the original switch is goosed and rather than find a replacement someone fitted the after market one.

Decide what temperature you want the fan to come on at, decide which of the switches you're going to replace and then find a switch with the temp range you require in the thread size you need.

90/92 on and 87/85 off is about the range you need. Have a look at intermotor for switches.

Then wire up with a relay. I like the option of the fan working without ignition in case of heat soak so have wired the relay with two permanent positive supplies and a switched earth via the fan switch, not to everybody's taste but it works and there's no battery drain.

Edited August 3, 2016 by steve in stockport

[Guest Jonnyround2003]

Yes it is

[Guest Jonnyround2003]

Hi Steve yes that's the case I have mine wired up like yours with the aftermarket switch but I think the temp range is too big as the fan runs for ages the thing is it's a 1/8 switch and can't find one that operates closer together in the temperatures you have stated