When I first bought this truck the gauges were all giving weird indications. The oil pressure was way low along with the voltage and RPMs. I found out that it was due to a loose ground wire running from the negative terminal. I tightened that up and all of the gauges now appear normal except the Coolant Temp gauge. My truck's temperature never seems to go above what I would guess is 160-170 as indicated on the dash and the truck performs better cold than when warmed up. I just replaced my thermostat thinking that it was to blame. No Change. The temperature still only tops out at about 170 degrees. I will replace the coolant temp sensor next. My question is could this be the cause of my trucks lack of power at temperature?