My 94 f150 has been acting up a little. The mechanic told me that everything was good with my cooling system, proper flow and all that. The temp gauge fluctuates between the o and the m on normal. It has gotten to the a befor and close to the l. Is that a bad gauge and it now does not have good heat, it is lukewarm. Even when the gauge says it is hot. Then in the middle of driving the gauge drops below the c on cold. What is this all bout. Again my mechanic. Said all is well.

 

Check both your heater hoses to see if they are the same temp that usually will tell you if the heater core is getting good flow through it.

I would replace the sending unit for the gauge and also the thermostat if you haven't already done so with a 192 degree one.

Also check the blender door to make sure that it is closing all the way.

 

The thermostat is new, what is the blender door?

 

There are blend doors that control where the air comes front to control your defroster to your vents are blend doors to control temperature around the heater core. If you can switch just fine between your defrost to the floor than that one works, but if the temp stays the same as you try and adjust the head **** then the actuator cable that controls it. Id still test your blend door. It will be on the firewall to your left, should have a little plastic arm that has a white hose going to it. If you adjust the ****, it should move.