Under the dash 68xr7

Hello again Cougar community. After crawling all under and around the dash I’ve restored drivers side dash lights … signal indicators dont blink on the dash (should they?) However, they do turn on the rear indicators

But the panel light switches are doing nothing. I bench tested and cleaned the switches and connectors and they do function. I also cleaned, tested and replaced the bulbs and sockets.

I also repaired and reinstalled the fuse box, checked for ground behind the dash, etc.
This particular ground wire seems to not be happy… i tried to trace it under the dash to the passenger side but i cant see where it terminates. I ran a fox and hound tracer to it and shes dead. And i ran a trouble light to it from the battery and also dead.

Got some other unconnected wires that werent obvious to me in the wiring schematic which I would also love to know what they plug into.

Like whats the fused orange line split, and where does the red wire go - or was that a PO tap and i should kill it?

And from the red plug is an unconnected blue/red(i think) wire. Feels like that needs a home.

And the 3 pronged connector …with red, yellow and brown wires in…should it have 3 going out? Does my dangling red wire without a pin go to that?

As always, i sincerely appreciate the group’s help!

The three prong connector is the connector for the rear window defogger option. If the car doesn’t have that option the plug just hangs there.


ok, so that’s interesting … So should I have even plugged in the yellow/brown pinned wires to it, to begin with? If those two were not for the intended connection, could you point me in the direction of where those should be plugged into instead? (the wires on the left in this photo specifically)

No idea where they go but not there. If you have a shop manual every wire color is described and every circuit has a schematic. You need one.

I have the shop manual and the classic car diagram … sometimes they are a little lacking!

Do you have any suggestions as to where to look as to why I’m not getting power to my panel switches?

Probably the interior lamp fuse is not making contact due to rust on the fuse panel. A dremel tool with the small brush can be used to remove the rust. Or you might try Evaporust gel from Harbor Freight. Either way the fuse needs to be removed first. Then install the fuse with a good dielectric gel to prevent future rust.

Thanks Royce. Wouldn’t this be fed by the same 2.5A fuse that’s supplying the driver’s side dash lights? I did dremel the rust away before reinstalling/reassembling the fuse box with all the other bits (like the K5 relay). and even made sure I had the factory-correct fuse in place.

The same one. Measure voltage on both sides.

Btw, is the low fuel light really just a single strand of wire wrapped in fabric? No wonder it breaks off - or is this just me?

It is a coil of nichrome resistor wire wrapped around a core and insulated in a high temp fabric sleeve… or was… You can replace it with a 50 ohm 5 watt resistor. Be nice to this stuff… it is expensive and hard to replace.

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I used a bit of solder to re-attach to the post. Hopefully, that didnt hurt it!

Looks like to me the sequential lights motor in the trunk is not working… I would recommend eliminating it and going with a solid state version… Turn Signal Sequential Unit - Solid State - LATE - After 1/2/67 - Repro ~ 1967 Mercury Cougar ( 1967 Mercury Cougar ) at West Coast Classic Cougar :: The Definitive 1967 - 1973 Mercury Cougar Parts Source

Just out of curiosity, are you running LED lights as the tail lights??

Stock bulbs. And until i got in there, no sequential unit at all. I picked up a working original … but the wiring harness in the trunk was butchered by PO.

If anyone can share a photo of what the harness should look like plugged into a 68 sequential relay i can make it whole again…in theory

Working 1968 turn signal apparatuses. I hope you can gather some information from it.

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This is perfect! Thank you so much.

Not sure if it was mentioned, but the turn signal indicators don’t blink. There is a relay offered by WCCC that will make them blink if that is important to you.
There are deviations from 67 (what I have) to 68 in the trunk. I have a 5amp circuit breaker that looks like ground connection when breaker is disconnected, so these are reasons why there are under detailed wiring schematics in relation to lights and other things like articulated lower front torsion bars.
Always do research for your year vehicle, it’s the little things.
Good fortune and great joy in your car.

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The white twist-apart fuse holder in the orange/yellow wire is for the turn signals (15A).

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I offer a pigtail repair kit (C8WY-13H366-AR) that includes the 12" wires with connectors needed to plug into the electronic sequential sequential system. The 5-pin emergency relay connector is not included because it is not needed for the electronic system.

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NiChrome wire is hard to solder. It can be soldered with silver solder.

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