Howdy.

On my 92 F-150 neither my Oil Pressure gauge or my Coolant Temperature gauge work correctly. Both are either not reading or reading way low.

What should I be checking? I replaced the coolant temp sensor located on the thermostat housing with a brand new one as the old one was completely corroded and covered in rust. Sadly it didn't seem to help.

Is there something in common with the two gauges? like a fuse? I think all my other gauges work correctly.

 

I wish you'd tell us what engine you're talking about. If it's a 4.9, the sender for the gauge is not in the t'stat housing. That is the sensor for the PCM.
The gauge sender for a 4.9 is on the RH side of the engine towards the rear, down in the water jacket.

At any event those two gauges share no wires.

 

Oh Sorry, yeah it's the 4.9 Liter Straight 6.
What's a PCM? When I went to autozone and asked for a new sender the one they gave me fit in the little pipe off the thermostat housing so I thought I changed the correct thing.

 

No, stay out of the zone. They're generally idiots, no more qualified to sell parts than to flip burgers, and their parts are the lowest grade of foreign junk.

Read these captions, especially the Temperature section of the first one:



Yes, the Volt, Temp, Oil, & Fuel, gauges are powered by Fuse 17 thru the R/Y 640 circuit.