Temperature gauge not working properly?

Does the engine temperature gauge go into the hot when the truck is first started? If so, the engine coolant temperature sensor might be bad but to be sure you can use a engine scanner to check to see what the engine computer is seeing. If it is normal, which should be about 80 degrees at first startup, then you will need to get a rebuilt instrument clutch which you can find by searching google or eBay. Here is the location of the coolant sensor and how to swap out the instrument cluster so you can fix the problem.

This guide can help out as well:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

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