Temp gauge/operation/wiring

[elgemcdlf]

Somebody way prior to my ownership has cut what I believe is the wire for the temp sending unit. Here is what I have. When the key is on & engine not running the temp gauge pegs hot. When the truck is running it settles back down to cold. I guess my start would be is this normal? Next on the list is I have gone through the schematics here for my truck (1970) & it appears as though the 3 wire plug has been removed so I have no reference as to what wire is what. I have a red wire that is currently connected to the oil pressure sending unit. Since my temp gauge never moves I am guessing this is correct. The cut wire I have is yellow. Does anyone know if this is the correct wire for the temp sending unit? I would like to connect my gauge but don't want to cook my ancient harness. Complete rewire is not quite here yet.

[DCrusher]

Somebody way prior to my ownership has cut what I believe is the wire for the temp sending unit. Here is what I have. When the key is on & engine not running the temp gauge pegs hot. When the truck is running it settles back down to cold. I guess my start would be is this normal? Next on the list is I have gone through the schematics here for my truck (1970) & it appears as though the 3 wire plug has been removed so I have no reference as to what wire is what. I have a red wire that is currently connected to the oil pressure sending unit. Since my temp gauge never moves I am guessing this is correct. The cut wire I have is yellow. Does anyone know if this is the correct wire for the temp sending unit? I would like to connect my gauge but don't want to cook my ancient harness. Complete rewire is not quite here yet.

Okay Red/White #39 is your temp guage White/Red #31 is your oil pressure Green/Red #16 goes to the coil these are the only wires going through the firewall right behind the radio right above and next to the throttle pedal the 3 pin connector should be there under the dash but if it's not there then forget looking for it and concentrate on the wire colors look for them Now back to oil and temp if you have the Red/White #39 hooked to the oil and your running a idiot light for OP then ya it going to peg immediately on the temp because it's the wrong wire that one should be on TS Just for kick unplug it does it change? If it does then we either have the wrong wire or the sensor is messed up. But it sound like you may have the TS wire hooked to the OP sensor because you describe it that your OP will be high when you first start it up as it gets warm it loses it's viscosity so pressure goes down at an idle.

[70_F100]

Have you thought about getting one of these? http://www.mustangsunlimited.com/itemdy ... 1=EGH18+01

[elgemcdlf]

Somebody way prior to my ownership has cut what I believe is the wire for the temp sending unit. Here is what I have. When the key is on & engine not running the temp gauge pegs hot. When the truck is running it settles back down to cold. I guess my start would be is this normal? Next on the list is I have gone through the schematics here for my truck (1970) & it appears as though the 3 wire plug has been removed so I have no reference as to what wire is what. I have a red wire that is currently connected to the oil pressure sending unit. Since my temp gauge never moves I am guessing this is correct. The cut wire I have is yellow. Does anyone know if this is the correct wire for the temp sending unit? I would like to connect my gauge but don't want to cook my ancient harness. Complete rewire is not quite here yet.

Okay Red/White #39 is your temp guage White/Red #31 is your oil pressure Green/Red #16 goes to the coil these are the only wires going through the firewall right behind the radio right above and next to the throttle pedal the 3 pin connector should be there under the dash but if it's not there then forget looking for it and concentrate on the wire colors look for them Now back to oil and temp if you have the Red/White #39 hooked to the oil and your running a idiot light for OP then ya it going to peg immediately on the temp because it's the wrong wire that one should be on TS Just for kick unplug it does it change? If it does then we either have the wrong wire or the sensor is messed up. But it sound like you may have the TS wire hooked to the OP sensor because you describe it that your OP will be high when you first start it up as it gets warm it loses it's viscosity so pressure goes down at an idle.

You are my hero. I had never considered the wire I had connected to the oil sending unit as the wire for the temp. It was / is too short to reach. I little tug to get more from inside the truck & it made it to the sending unit. Temp gauge works as it should. Oil is an idiot light & I am assuming the other wire (cut off) is the oil pressure wire. I will extend it & connect it as well. Oh happy day!