thermostat stuck open?
 

i was pulling a trailer with some topsoil today and notice when i take off my Engine temp drops to C and even when im drinving down the highway it stays below normal.. does that sound like a stuck open stat?? i live in Texas so the temp aroung here is about 90

Maybe a bad temperature sensor also.

Unplug the temp. sensor and see what the temp. gauge says. Then ground the lead, the gauge should go the other way full swing. If so, replace the t-stat. That's the way we used to test them anyway.

What gauges do you have? Or are you using the in dash idiot gauge to see the coolant temp?