91 f150 temp guage

Im trying to replace the factory temp guage with an external guage. I looked in the manual and it says the temp sensor is in the top of the block between the distributor cap and the oil fill. But its not and I cant seem to loacate it anywhere else...any ideas?

Thanks,

Scott

There are two temp related sending units on this truck. One is called the coolant temp sending unit, has one wire, and should be just to the right of the dist. The other is the engine coolant temp sensor, it has two wires, and should be to the left of the dist. The temp sending unit with one wire is the one you want. If you use the other, it will cause driveability problems, because it sends info to the computer to help control spark and fuel delivery. If you have the 4.9, it is located at the rear of the block under the end of the exhaust manifold. Good luck.
Later
Ed

I do have the 5.0 and the only one I can see is to the left of the distributor. There wasa sensor just to the back of the distributor but we pulled that out and it seems to be some other sensor..it had oil on it. I dont see anything else with only one wire coming off of it besides the oil temp sensor which is on the side of the engine by the filter.

If your temp gauge works now, its gotta have one somewhere. lol Someone could have could have installed one in a different spot, but thats where its sposed to be. Look on the front, sorta down under the dist, seems like the 351s were there. But you can mount your sender/thermocouple for your new gauge any where you can find a plug that goes into water, it doesnt have to be in the original spot unless thats the only one available. Look on, and around the thermostat housing, there may be a plug there you can use. Or you could put a thermostat housing from an earlier model that had the plug. good luck.
Later
Ed

The temp guage that is in the dash hasnt worked since i bought the truck, this is why im putting an external on so i can see if the truck is going to overheat pulling a cmper home from up north memorial weekend.. I will look around some more tonight.

Ok, the sensor that you pulled out that looked like it had oil on it, is probably it. There shouldnt be any other sensor there. Did it have one round stud sticking up in the middle? Take it back out, and fill the radiator and see if water runs out . If it does , then youve found the spot. There shouldnt be any holes, or plugs, or sensors up there that go into oil .

No it didnt, it has a two wire connection on it. i will look around more tonight.