Just reinstalled reworked heads on a 2001 Ford F-150 4.2L and now the oil pressure gauge and temp gauge are not working and their respective lights are on on the dash. I have a sensor that after I installed the heads and intake manifold, I found that my step-father had set off to the side. It is a little black box on one end with a plug-in connector on the other. The plug-in end connects to a plug with a red wire on the harness coming from the wire loom on the passenger side of the engine. I believe it was attached to the rear of the passenger side head. Could this be the problem and can I ground it elsewhere?

 

Just an update for you all. OK., the temp gauge IS working. It is the oil pressure gauge that is not working. Also, now I have a battery light on as well. I have checked all connections to the alternator and they are good as well.

 

I can't help with this one. I'd suggest a Haynes or Clymer or Ford manual and just go about tracing all the wiring that would have been involved.
Sounds like it might be one of those cases where there ain't a short cut.

Unless somebody chimes in and knows exactly what you ask about.

Good luck with it.

 

I'm wondering..... When I got the heads back from the machine shop, they painted them. There is some kind of sensor on the driver side head on the rear of the head, I'm not sure what the sensor is, but I noticed that is WAS white plastic, but when I got it back, It had silver or grey paint on it. I wonder if paint got on the inside of the sensor and is causing it not to get a connection. Like I said, I don't know what the sensor is. I have looked through the Hayes manual with no luck.

 

Cylinder head metal temp sensor.

 

Where is this located at?

 

Rear of cylinder head.