The temp gauge on my 2008 ram 1500 jumps from normal temp to hot checked engine the temp is fine my heater them puts out cold air and I have no heat if I shut heater off and wait a few minutes temp gauge goes back to normal and everything works fine for a while

SOURCE: Heater doesn't blow hot air

First check the coolant level in the radiator. Check your heater core hoses on the firewall underneath the hood. Let the car come up to temp. and feel the two hoses. If only one of them is getting hot you may have bad heater core or a bad heater control valve.

SOURCE: The heater is blowing cold but the engine temperature reads high

Hi
I would first check to see if both heater hoses are hot to the heater.
if 1 is hot and 1 is cold the heater control valve is closed or the heater core is plugged.

SOURCE: 99 Dodge Ram 1500: Engine starts but then immediatly dies.

Sounds like a fuel issue. If it only does it when it's cold try putting some heet in your tank?

SOURCE: 2006 dodge ram 2500 heater not blowing hot air....

it sounds more like the thermostat, a thermostat will cost around 8 to 12 dollars,just remove the thermostat housing and replace the old thermostat then reinstall the housing

SOURCE: 2001 dodge stratus engine temperature gauge spikes occasionally

Look for a loose connection to the temperature sender unit on the motor.
If all connections OK, you may need a new temp sender unit.