Check youtube for the videos on changing the heater core on a F150. A portion of the change includes removing the cluster from the dash. You may have to reseat the connector or chase a ground to solve your problem.
Depending on how it is wired, most gauges are fed power by dedicated feeds and have common grounds. If the ground is bad then you loose multiple gauges at the same time. You can lose the ground just about anywhere, from the back of the cluster to where it connects to chassis ground and anywhere in between.
Hopefully Ford hasn't networked the gauges (CAN2.0). If so that is a different animal.