I will get photos as soon as the weather allows.
As for the contactors... Before the tub stopped heating, the contactors started clacking non stop. So in hopes to prevent further damage I cut the breaker to the tub and shut it off. This unit has two contactors. One is a pole and a half. The other is a two pole. When I began troubleshooting, I determined the two pole wasn't making connection on one side. When I removed it, I took the cover off and the contactor fell apart. One side was completely broken and in pieces. I thought I had discovered the problem. However, upon replacing the contactor I still have no heat or light. Note: the control panel on this unit has a "ready" and "heat" light, both of which are dark at all times. The "jet" and "blower" lights both are still on and both those features function correctly.
I do not see a flow switch like the one in the photo above anywhere on the unit.
I do have a multimeter.
Thank you all for the comments and feedback!