97 2.3L only warms up driving, Drops to C at idle

I have been battling this issue for a couple weeks now and it's really starting to get on my nerves. Ever since it has gotten cold here in MN my ranger wont warm up. It only warms up to operating temp while driving and when I stop at a stoplight or just let it idle the temp gauge drops down past C pretty quickly and you can feel the heat coming out of the vents get lower. While the truck is trying to warm up after i start it I can feel the top radiator hose get somewhat warm and the lower radiator hose is cold. IDK is my new t stat is maybe stuck partially open or if maybe some coolant is leaking by.

Truck info:
1997 Ranger 2.3L 4x2 5 speed

New Parts:

T-Stat
Waterpump
Radiator Fan Clutch
Timing Belt
Accessory Belt
Coolant

I have flushed the heater core a couple times also and I do get good flow through it. I have also found that my alternator is on its way out but I dont think that has anything to do with it.

I am starting to get very frustrated with this issue as nothing seems to fix it. If anyone has any ideas that would be great!

:sombrero: