The Ford Barn

koates · 01-08-2022, 10:34 PM

Graham, some of the already posted information is not exactly correct. The two lower and longer terminals are for the heavy ammeter wires, so on a 34 with the metal loop on the back of the original ammeter you would have to cut the wire that goes through that metal loop and fit eyelet terminals to fit the two wires on to your oil chex ammeter terminals. The two top terminals which are very short and for the oil gauge, only have the sender pressure switch wire connected to the terminal on the left side ( looking from the back or rear of the gauge). The terminal on the right is not connected to anything external, but is connected internally inside the case. It is important not to loosen this terminal because the wire inside could be damaged or broken off if you do this. I have come across several of these old gauges where the internal coil for the oil gauge is open circuit or broken and the oil drum wont work. The sender is a pressure switch which has to have normally open contacts with NO OIL PRESSURE. The contacts close when oil pressure is applied with engine running. This is opposite to oil light pressure switches. I use a TRIDON TPS 065 switch which closes its contacts at 8 PSI. It has a single terminal on top like the originals. Has 1/4 X 18 NPT fitting. If you buy another brand of switch be carefull its switching pressure is not too high. Regards, Kevin.

01-08-2022, 10:34 PM	#7
koates Senior Member Join Date: May 2010 Location: Melbourne Australia. Posts: 2,218	Re: Oil Chex Gauge Graham, some of the already posted information is not exactly correct. The two lower and longer terminals are for the heavy ammeter wires, so on a 34 with the metal loop on the back of the original ammeter you would have to cut the wire that goes through that metal loop and fit eyelet terminals to fit the two wires on to your oil chex ammeter terminals. The two top terminals which are very short and for the oil gauge, only have the sender pressure switch wire connected to the terminal on the left side ( looking from the back or rear of the gauge). The terminal on the right is not connected to anything external, but is connected internally inside the case. It is important not to loosen this terminal because the wire inside could be damaged or broken off if you do this. I have come across several of these old gauges where the internal coil for the oil gauge is open circuit or broken and the oil drum wont work. The sender is a pressure switch which has to have normally open contacts with NO OIL PRESSURE. The contacts close when oil pressure is applied with engine running. This is opposite to oil light pressure switches. I use a TRIDON TPS 065 switch which closes its contacts at 8 PSI. It has a single terminal on top like the originals. Has 1/4 X 18 NPT fitting. If you buy another brand of switch be carefull its switching pressure is not too high. Regards, Kevin.