Temp gauge acting funny and van surging

hi
we live/drive on dirt roads. lots of shaking. '00 astro van started slightly hesitating and the temp gauge would drop. temp gauge would come back to normal and van would run as it should. on pavement it runs ok until a rough spot.

now the temp gauge shows no temp. van seems to run fine.

noticed some sort of sensor on the driver's side of the upper coolant hose and thermostat housing. ideas what the senor might be?

is the temp sensor on driver's side of engine block?

thanks

dick

Your 2000 4.3L has 2 temp sensors. The one for the ECM is located next to the thermostat housing. The sensor for the temp gauge in the dash is located in the driver side cylinder head between cyls 3 & 5. Two totally separate circuits, not related to each other in any way.

Might want to check the connections behind the underhood fuse panel, common for them to corrode and loosen up. There's a wad of red wires back there, check them all very close.