14289 Wiring Harness Help - Oil Pressure Switch

[RootBeerJoe]

I recently purchased a 1967 Cougar XR7 which was sitting for about 1.5 years that I am trying to get running. One of the problems is that many of the wires under the hood are deteriorated. Right now I am trying to replace the wiring harness listed as 14289 assy in the shop manual. I have the replacement in hand but have a question I am hoping someone here can answer. This wire assy has three wires in it and connects with a red connector near the firewall by the brake master cylinder.

The red/white wire goes to the temp sending unit.

The red/green wire goes to the ignition coil.

According to the shop manual wiring diagram, the last wire with the spade plug should go to the oil pressure switch. On my car it is unattached and just taped over with electrical tape.

I find this odd because I have an oil pressure gauge in the dashboard which is working.

Should I just tape over this spade plug or is it supposed to be attached somewhere?

Thanks for any help.

[fordnutz]

The oil pressure sending unit attaches to an extension on the driver side of the engine just beside and up from the fuel pump. The spade plug attaches to the end of the sender.

[JETEXAS]

Is the working oil pressure gauge an aftermarket unit? Someone might have changed senders and run a new wire to that gauge. I believe there’s a different sender for the pressure gauge versus the dummy light.

[fordnutz]

All 67-70 XR-7s have a gauge, non-XR-7s have a light.

[RootBeerJoe]

Thanks. I will look for that.

The oil pressure gauge is the stock gauge. Not sure why it is working if this wire is unattached.

[fordnutz]

Does the gauge move with RPM?

[RootBeerJoe]

Yes. When I start the car the gauge rises to about 55. When I rev the engine it rises to about 60 at 2500 rpm.

I’m not even sure what it should be. I looked in my owner’s manual and shop manual and could not find a #.

[fordnutz]

You need to check out the sender. Maybe there’s another wire hooked up to it going to your gauge. Maybe the original was bypassed for some reason.

[RootBeerJoe]

Ok. Thanks. I am still trying to locate where to hook it up. I found the fuel pump but still are unsure about where this wire goes. Ill keep looking.

If you know of any diagrams or photos that show where to hook it up I’d be grateful for a steer in that direction.

[fordnutz]

I am not available to take a picture to post, but your 1967 factory shop manual will be of great help to you.

[RootBeerJoe]

I wasn’t able to find it in my shop manual but I am in the process of updating my coolant system and have the front of the engine bay opened up with the radiator, alternator, and fan out of the way in order to get to the water pump. Maybe I’ll have better access to see what I am looking for with all these things removed.

[fordnutz]

Here is a picture I found on the web. I hope this helps.

[RootBeerJoe]

That picture is a big help. Now I know why I can not find it. Mine is different. My car does not have this bell looking device on the end of the rod.

Instead the end of my oil sender has a plastic hose attached to it:

and then the hose continues up along the driver side fender and then through the firewall.

What’s the deal with this? I guess I just leave that third wire taped off.

[cougarrand]

Your sender is for an aftermarket gage. Installed by a prevoius owner.

[fordnutz]

If your original gauge in your cluster is still there and operational (maybe that was also changed out by a PO), you could put in the correct sender and hook up the wire and put it back to stock, if desired.