It doesn't go to the middle till after I park the car when I've gone for a drive.
When I'm driving it looks like it's going to start moving up but then it drops to C
Can the sending unit be bad?
Anyone else have/had this issue?

 

try this first: disconnect the wiring harness, clean the contacts and put it back together.

 

Cool,Thanks TanP!!!

 

Disconnected & cleaned & now the needle goes up while car is warming up then down when I'm driving and the heat & rear defrost are on.The heat isn't blowing hot either after the car has warmed up?
Anyone else have this kind of issue?

 

That's getting weird. I would like to find out if the gauge is lying. You would need a temperature probe in order to take measurement under the hood. Before and after the thermostat and heater hose in and out of the heater core, for example.
Then there could be a wiring problem along the wires too. You know, shorts. there could be a wire to wire short or a wire to body short etc. One of the better ways to track something like that down is doing voltage drop tests.

This is one of the better descriptions of doing voltage drop testing: Voltage Drop Testing

What if the gauge is telling the truth? You may have a problem with air in the cooling system or plugged lines, or faulty thermostat.

 

If I understand you correctly, it sounds like your thermostat is stuck in the open position and your engine it not heating up properly. If you let the car idle for about 5-10 minutes, the cooling fan should kick in. Normal reading on the gauge is about 1/3 from the bottom C. Defroster uses AC, so the test would be the heater. If the valve is turned all the way to the right (red area) and the car has run for about 10 minutes, you should have hot heat if you set the air outlet for floor or dash (no defroster). If it is still cold, I would suspect the thermostat is stuck open which does not allow your car to properly heat up during the colder days.

 

The needle started doing that before I replaced the stat last summer
AC is full of refrigerant but doesn't blow out cold either
I'm gonna replace the stat & possibly the temp sensor also since they're not too expensive
I'm stumped with this one here lol

 

just replace the thermostat first and evaluate. its not a good idea to replace many things at the first time because you will never be sure what action fixed the problem.

 

I agree! One thing at a time or you'll never be able to tell what's wrong with it.
And yes, it does sound a lot like a crappy thermostat to me too... even if its new, or almost new.

As for the A/C, well the car is 20 yrs old, but you are liable to need some parts and an evac to fix it. If the compressor is running, the system is full of refrigerant, but its not blowing cold, the first place I'd look would be the expansion valve. Do the receiver/dryer at the same time and have the system professionally evaced before adding the refrigerant back into it.

 

But the thermostat is new.

Maybe it came from the land of sweet and sour chicken?