NEEDING Temp Gage HELP

[shanicmer]

Hey I have a 96 Max GXE and I am having a tough time finding out why my heat and temp gage only goes up to normal when I am sitting still. When I go down the road my temp gage goes down to about nothing and the heat in my car drops as well. I tried putting something behind the grill but that didn't seem to help. Any ideas? Also my heater dosen't put out as hot of air as it should. Any ideas on that? One more thing...I need to replace the rear struts and there seems to be like a lock nut in the way of the bottom bult. Is that normal and if so is there a way to get it off without taking the whole brake and rotor off?

[chmsl]

Have you checked the condition of your cooling system? Make sure
you are topped off and there are no leaks. You may have air in the system
and this would cause the low to no heat symptom.

[mmcleo11]

Cooling problem: Thermostat is stuck open or has been removed.