P38 Range Rover Low Coolant Alarm, Float Version

This describes a method, used by WANYEG from aulro, which utilises a float switch
Sensors You will need a float sensor from ebay, like the one below.	Drill a hole in your expansion tank, Please make sure its as close as possible to the shank of the sender. Fit the sender in through the expansion cap orifice, wire up through the relay to your warning device. The float is on in the coolant full position and switched off when low on coolant. You need to keep the sender float as low as you can in the tank so you cant just turn it upward. the relay resolves this. This is how it looks going off! All feedback, comments and corrections are very welcome, send to the email address in the home page.
Alarm A couple of flashing LEDs	Click on the image for a larger version
You will also need a 5 pin relay	Click on the image for a larger version