Just installed new auxillary guages cause my stock gauge wanted to wander around. Now the new guage with all new lines ran want to wander. The set of guages i bought are a cluster of 3. your basic volt water and oil. I have them ran to tap into my stock guages except for the temp and the temp wants to go up to 240. my truck is a 1997 ford f350 with a 460. any help is well needed!!

 

If the temp gauge wanders alot, maybe the thermostat is acting up. Some fluctuation is normal. If you replace it get a stock temp one.

 

Air in the cooling system could cause a wandering temperature gauge. Or a defective temperature sender or associated wiring.

Remove the wiring at the sender and then ground the sender wiring with the ignition on-the gauge should peg to hot . If the needle wanders with the wiring grounded-the wiring or gauge is going open intermittently. If the needle stays pegged-then the wiring is good-check the sender with a VOM and look for wandering changes in resistance to ground.

If both the gauge and sender/wiring checked out --check for air in the cooling system. Is the coolant up to the neck of the radiator when the engine is cold? Is there coolant in the overflow reservoir when the engine is cold ?

My truck has a wandering temperature gauge like this immediately after changing the coolant and when there is still some air in the cooling system that hasn't been burped out yet. .