I always recommend to get your truck scanned and troubleshoot the code that is getting logged. You likely have a temp sensor faulting. The coolant temp sensor on your dash is the same the engine reads from, so if that is ok, it is probably the oil temp sensor. The oil temp sensor in the dash is different from the one the engine ecm reads from. So if you have an oil temp sensor and it reads fine, or you don't have that option, this is why. But as for now, you are chasing a ghost until you know what code is getting logged.
HeavyD I'm wondering the purpose of the wire that goes past the reverse sensor on top the transmission it goes back a ways then ties together with a diode why? Wondering if I can't take it off and hook up a backup alarm? 9900i
I checked over a few diagrams and nothing is showing any diodes for that circuit. I don't ever recalling seeing diodes for that either. Check the wiring to see what colour it is and what number/letter it is. In my diagrams, the reverse light switch circuit deals with orange wires numbered 71 after the switch connector.