Does anyone know at what temperature the coolant temperature switch is activated? If it is not too hot when it switches on, I would like to hook my electric fan relay to it, instead of turning on whenever the truck is on.
I made a single relay harness and wiring for an electric fan I put into my 85 2.3l ranger to replace the clutch fan.
Dustin
A Ranger doesn't have a temperature "switch", it has a Sender for the Temp gauge on the dash, and if fuel injected it will have an ECT sensor as well.
Neither is a "switch", i.e. on/off, both are variable resistors, so neither goes to 0 ohms(ground)
Best bet is to add a temp switch or use a relay temp sensor that inserts into the rad fins
Temp switch, is "Open" until it reaches a certain temp then "Closes" to Ground the connected wire.
So on your relay you will supply relay with 12volts key on, then run the relays ground to the temp switch, when temp switch closes relay will also close and power up your fan
These are used to insert a temp switch into the upper rad hose:
https://www.amazon.com/s/?_encoding=UTF8&camp=1789&creative=390957&field-keywords=autometer radiator hose adapter&linkCode=ur2&tag=viglink24555-20&url=search-alias=automotive
Many import cars used these so check wrecking yards
Temp switch part here:
http://www.ebay.com/itm/185-To-175-Degree-Electric-Engine-Cooling-Fan-Thermostat-Temperature-Switch-/311625285473
This single wire switch needs to be grounded, so when using a "bung" as shown above you need to add a ground wire to that bung since it is on the radiator hose and has no natural ground to engine.
This type needs to be mounted closer to the engine than radiator if practical, and you want the temp switch to always be IN the coolant, so mount it on its side, so if a little air gets into hose switch will still be IN the coolant.
This is example of rad fin insert switch:
http://www.ebay.com/itm/Flex-a-lite-31147-Electric-Fan-Temperature-Thermostat-Switch-Adjustable-/191618608304
These have an adjustment to set the temp it "closes" at, because where you place it in the rad matters
general speaking you want the fan to start working when coolant in the engine is around 185degF on a Ford, thats about when thermostat opens and coolant start to flow thru the radiator, no need for fan before that happens