Hey people was wondering what else besides a thermostat(this is what I think it is) would make my temp gauge fluctuate it's not runnin on the hot side it's the opposite it's up and down on the cold side of the gauge lime I said think it's the thermostat stickin open but just in case was wondering what else it could be gonna change it out this weekend thanks alot

 

Not sure if that is the thermostat, but my 96 F150 is doing the same thing. The gauge never goes past the R in NORMAL, but it moves between the N and the R. The weatherman is calling for snow this weekend, so I am in no hurry to pull the thermostat, yet.

 

The gauge is controlled by a coolant temp sensor. If the temp reading is inaccurate, that is the cause.

 

So where would said sensor be located don't get me wrong gonna go ahead and swap the thermostat regardless might as well but would lik to look into the sensor also

 

Actually to stand corrected, there is both a sender for the gauge, and a sensor for the computer. The gauge is controlled by the temp sender which has one wire. I have the 4.9 engine, on my truck the sensor is on the thermostat housing, the sender is on the block somewhere. On the 5.0 I think the sender is near the dsitributor.

The 4.9 has a stock thermostat of 195 degrees. I don't know about the 5.0

 

Right on thanks come to think of it think I seen a wire on the thermostat housing might b wrong just took a quick look at it yesterday before I started work thanks again

 

The sensor right there by the thermo housing is the one for the computer. If it's bad, it should throw a check engine light though. It's not a very expensive part to replace though, I doubt the sender is either.

 

It will do that if it's low on water too.