7.3 engine temp light
 

Have a 95 350 with 7.3 Have a engine temp light on that is on right side of dash below the wait to start light. Ford does not know what it is . I have a bad sender but need to know were it is. Checked for codes . Nothing. Stumped.

There are several variations with the instrument cluster.
It is important to know just what model vehicle you have.
Is it an E, F , F Super Duty or F Super Duty Motorhome ?
On some clusters that position you describe is a blank.

If you have your owner's manual, it should cover that, should!!
If you don't have the manual you might try ,http://www.fleet.ford.com/partsandservice/vin-decoder/ where you can enter your vehicle's info and view the manual.

engine temp light
 

It is a F-350 XLT crew cab dually. It is not in the owners manual and three ford truck dealers have no idea what the light is for. It is not on any of their wire schematics. That is way I am on the forum. I need positive input. I am a ford mechanic.

Did you purchase this truck new? If not, do you know where the previous owner got it?
The reason I ask this is because if it was a former ,rental truck, they are many times ordered with special equip, (SE) and info for them is not easily available. Been there , and only the rental co had the info for their special equip.

I bought the truck new. Am the only one that drives it. Have 268,000 miles on it and the light has never come on before except in pre-start mode.The light comes on after driving a few minutes. when you first turn on key. on with all other indicator light. Some times dims and then gets bright. It is not on constantly until after starting. No pattern or reason for it. The engine is not warm. all fluids at levels. Need to find sending unit that operates light!!!!!

Have disconnected battieys to see if it resets. Came back on ofter about 10 seconds. My fellow mechanics who are trying to help agree that we need to find out what engine temp it is. Is it oil or another water sender??? Them we could eliminate a system.

I have been unable to find any addl info for that particular position on the cluster.
Unless your cluster definitely shows the following , it could be one of them
Water in fuel filter
trans oil temp
Turbo related
Of course it could be something else is using that light for it's ground especially since it never illuminated in all those miles.

this is no help. I said the light has always came on with other lights when the key is first turned on so the short has to be in the sending unit that it is connected to. There has to be another wiring schematic some were. I have all of the ford tec manuals. All seven. And none of these have this in it.

Depending on how determined you are, trace from the printed circuit that feeds the lamp back to the color wire on the plug then trace the color back to it's origin. Not that difficult to do. You could also start removing plugs from various sensors one at a time (not recommended to do with the key on with later vehicles) until the lamp goes out provided your theory of a shorted sensor is valid. What does the info on the lamp say?

Its the Overheat Warning Indicator lamp..

Switch closes and illuminates the lamp when the engine temp hits 247'. Switch is mount forward of the engine left side. S/B a W/LB single wire connector. Switch probably shorted out..