Quick question -

I have temp sensors for the ecu and the dash on my car and I am currently doing a bit of re-plumbing. The car has the usual warm up circuit through the heater and then the thermostat opens the main circuit through the rad. Would it be a good idea to put the ecu sensor in the main circuit (so the fan comes on only when the rad is up to temperature) and the dash sensor in the warm up circuit (so I can see the difference) ?

All comments welcome.

What is the ecu controlling exactly?

Ecu is an omex710, controls engine, fuel pump and rad fan so uses the temp sensor for warm up fuel enrichment / cold start. So if in the warm up circuit the ecu would drop out of cold start sooner than in the main circuit.

Hope that helps

[Edited on 12/7/16 by Ugg10]

Ah right. Both the gauge and ecu sensors need to be in the head, or at least in a location that *always* sees the hottest coolant coming from the head. The ecu sensor in particular must not be in a circuit that is interrupted by the thermostat. You can put your gauge sensor in the thermostat controlled circuit if you wish but I don't see any point in that.

Many thanks, makes sense as the OEM sensors are in the manifold at the top of the head, will put the ecu as close to that as possible. May still put the dash sensor in the main loop just so that I can tell when the thermostat opens (or not).

Hi
I have left the main sensor (ecu) in the head where Ford put it, i have a fan switch at the radiator and the dash gauge is on the return pipe.
I think the dash gauge is more for your observation and to note when its not normal as it controls nothing, its just early warning.
Im just about to set up my digidash and im a technophob but my peace of mind is it doesnt really matter that much how accurate the original readings are as long as you note when they arent.

Nick M