The temperature gauge on my 2001 ram 1500 dodge truck goes up and down continually . Is the thermostat sticking?

Ensure there is no air in the system--it can play havoc with the temperature gauge and other sensors. If that's not an issue, then this link may help:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-11.html#post2043857