57 under hood wire routing question

[Pink T-Bird]

Trying to figure out 2 things to get my underhood wiring back to what it should be.
First - the oil pressure idiot light had been replaced with a gauge that uses a capillary tube by a prior owner. I have nothing against gauges, but I'm a belts and suspenders kind of guy and would like the light to work.
The light socket has power an a good bulb. A white wire that should go to the sending switch from the bulb socket routes up into the main harness and disappears. That seems stock/normal. It never comes out at the other end under the hood. I presume it was cut off and taped over in the underhood harness, Where should I look for it? Seems logical it would either be: with the wires that come from the firewall to the temperature sender and ignition resistor; or, be with the brake switch wires since they go down to almost the correct location. Before I start cutting off the black wire wrap I thought it would be a good idea to ask here if either of these are correct.
Second - the T&C radio works, but the volumatic wire is cut and coiled up at the radio. I can buy a replacement volumatic lead with the correct coil adapter, but how does that correctly route through the firewall to the coil?

Thanks!
Greg

This page contains affiliate links for which I may be compensated. As an eBay Partner, and Amazon Associate I may be compensated if you make a purchase at no cost to you.

 

[valhalla 4771]

Trying to figure out 2 things to get my underhood wiring back to what it should be.
First - the oil pressure idiot light had been replaced with a gauge that uses a capillary tube by a prior owner. I have nothing against gauges, but I'm a belts and suspenders kind of guy and would like the light to work.
The light socket has power an a good bulb. A white wire that should go to the sending switch from the bulb socket routes up into the main harness and disappears. That seems stock/normal. It never comes out at the other end under the hood. I presume it was cut off and taped over in the underhood harness, Where should I look for it? Seems logical it would either be: with the wires that come from the firewall to the temperature sender and ignition resistor; or, be with the brake switch wires since they go down to almost the correct location. Before I start cutting off the black wire wrap I thought it would be a good idea to ask here if either of these are correct.
Second - the T&C radio works, but the volumatic wire is cut and coiled up at the radio. I can buy a replacement volumatic lead with the correct coil adapter, but how does that correctly route through the firewall to the coil?

Thanks!
Greg

Greg,
I'm pretty sure behind the radio there is a small hole through the firewall near the the lip of the hood, in line with the distributor....assuming the wire controls the volume as the car speeds up and slows down. Don't ask me what it connects to....the distributor maybe. Auto electricity is a black box to me. Good luck.

 

[jack-in-sac]

Trying to figure out 2 things to get my underhood wiring back to what it should be.
First - the oil pressure idiot light had been replaced with a gauge that uses a capillary tube by a prior owner. I have nothing against gauges, but I'm a belts and suspenders kind of guy and would like the light to work.
The light socket has power an a good bulb. A white wire that should go to the sending switch from the bulb socket routes up into the main harness and disappears. That seems stock/normal. It never comes out at the other end under the hood. I presume it was cut off and taped over in the underhood harness, Where should I look for it? Seems logical it would either be: with the wires that come from the firewall to the temperature sender and ignition resistor; or, be with the brake switch wires since they go down to almost the correct location. Before I start cutting off the black wire wrap I thought it would be a good idea to ask here if either of these are correct.
Second - the T&C radio works, but the volumatic wire is cut and coiled up at the radio. I can buy a replacement volumatic lead with the correct coil adapter, but how does that correctly route through the firewall to the coil?

Thanks!
Greg

The oil pressure sender will likely have a female spade connector at the sensor end. Is there still a pressure switch in the block or has it been replaced by the fitting for the capillary tube? If the sender has been replaced you could remove the capillary fitting and replace it with a short piece of pipe threaded pipe with a "T" fitting allowing use of both the capillary tube gauge and the oil pressure light. As to finding the sender wire look for the correct color wire that is loose, ie/ not attached.

 

[richsfords]

in the engine compartment centered on the firewall, coming from the wire bundle, a red/white wire and a red wire. r/w wire goes to the oil pressure switch. all red goes to the heat sensor on the manifold. I have just rewired my 57 and that is the way it goes, everything works🙂.
Rich

 

[Pink T-Bird]

in the engine compartment centered on the firewall, coming from the wire bundle, a red/white wire and a red wire. r/w wire goes to the oil pressure switch. all red goes to the heat sensor on the manifold. I have just rewired my 57 and that is the way it goes, everything works🙂.
Rich

Thanks! With your description I found the cut r/w wire stub right where the red wire exits the tape harness! A small length of electrical tape had been added to the harness to cover it. I can peel it back a bit further and do a proper solder splice. I found the reproduction lead for the oil sender with the spade connector so I ordered that and I should be set once I install the pressure switch and the T.

 

[Pink T-Bird]

Greg,
I'm pretty sure behind the radio there is a small hole through the firewall near the the lip of the hood, in line with the distributor....assuming the wire controls the volume as the car speeds up and slows down. Don't ask me what it connects to....the distributor maybe. Auto electricity is a black box to me. Good luck.

Valhalla,
I think I found it with your description - It's actually directly behind the coil, really really high on the firewall, obscured by the wiring harness to the voltage regulator. There is a hole just barely large enough for the RCA connector to pass through with a rubber grommet to prevent chafing of the wire.