The first step is to replace the cougars fuse link and use this circuit diagram for reference.
*****************shunt diagram ************************
A more detailed description of how the shunt and power distribution is used.
Located in this post here.
https://cccforum.discoursehosting.net/t/start-run-charge-power-distribution-circuits/2512/1
My cougar is an XR7 and has the ammeter gauge that uses the shunt circuit above.
Surprisingly the T-Bird is exactly the same but with one exception.
The shunt wire on the T-Bird is bright yellow and the rest of the circuit is the same right down to the circuit numbers and colors.
The shunt wire on the cougar is black, or it could be black with orange stripe, I have seen this difference of wire color on a few cougars.
You can find the shunt wire on the XR7’s only, and if you were to start at the solenoid, Right where the battery cable is connected to the solenoid is a smaller rubbery skinned wire with a plastic incased crimped on connector.
That is the first end of your fuse link wire and that is the wire that will pop when a short circuit occurs, it passes power to the whole car and everything will go dark.
Fortunately the power windows are not on that fuse link and if you have a convertible, the top will still go up because they have their own circuit breakers.
You can test this wire to see if it is open by giving it a stout but loving tug.
The wires outer skin is designed to be more resistant to bursting into flames and will stretch easily when it is blown out.
!!!Tug just hard enough to test the connection. !!!
Some of you might look at yours and find that it has a bit of a curly look to it.
That means that it has had a big load on it at one time that causes that.
If your stout but loving tug pulls the wire apart then you may have found that cursed intermittent power glitch problem.
The fuse link is about 3 or 4 inches long and if you follow it to the first plastic splice in the wire you will see a big wire and a small red wire.
The big wire is the beginning of the shunt wire and the red wire goes directly to the ammeter in the dash.
Looking at a factory wrapped harness you might notice that the shunt wire is the big one that is folded back on itself and can sometimes be seen without unwrapping.
Following the big black wire further up you will find another plastic splice with a small yellow wire and another big black or black/orange wire all in that splice.
This is the end of the shunt wire and that yellow wire is the one that goes directly to the ammeters other terminal.
Then from the same plastic splice there are two big black wires with one of them routing back to the alternator connector and then the other one goes into the dash to the ignition switch connector.
I have had many people ask me in the past about ammeters so I included the brief explanation so that people that are working on their cougar wiring systems for the first time can find it and understand the next few pictures and paragraphs.
At the time that I was stripping the T-Bird harness I left the shunts in place just in case I wanted to use the T-Birds shunt to monitor current draw for the EEC system.
But it is just too much big wire to add under the hood and there are other ways to monitor current draw so it is time to cut it out of my circuit and hook it all up.
Here is what I had just before using the cutters to remove all of the fuse links and the ammeter shunt;
I did leave the cut out shunt and fuse links intact just in case I need one for some other project in the future.
before cutting*
The cut off ends from the EEC systems were then routed to the new fuse box and the fuse link that fed the cougar is removed and connected to the new box also.
With the power feeds hooked up it is time to move on from that second splice mentioned above, {the end of the shunt with the yellow wire.}
I now need to hook up the charging circuit to the big wire from the shunt and another smaller green wire to a hot in run circuit.
On your stock cougar is the alternator/regulator harness that plugs into the main cougar harness.
If you follow the big wire from the back of the alternator you will come to a two pin connector that has the big black wire and on the other pin is a smaller green wire and it may have a small yellow wire as well.
I will now use that plug so that I can plug in a converted alternator harness.
I used a grade “F” alternator harness that had nicks, cuts and missing pins for a sacrificial donation for modifications.
***************** picture of main cougar harness******************
After cutting off the regulator connector and the one piece mount at the alternator I now have a plug that I can convert to the newer alternator with the built in regulator.
*********cut off alternator harness
The original alternator and regulator harness was not harmed during this modification and has been put up in a special place on the garage wall just in case.
The plug saves me from hacking the main harness.
modified alternator harness
I can now add a round crimp connector on the big black wire that will go to the B+ connection on the back of the alternator.
The smaller green wire is hot in the run position and will connect to the alternator exciter circuit.
The other small yellow wire will be used to activate a relay for other circuits that will need a hot in run signal such as the EEC system.
The relay will help to keep the cougar system separate from the T-Bird parts.
***************WARNING ***********************
If you pull the dash from your XR7, the back of the ammeter gauge is hot at all times. There is supposed to be a cover over them, if not put one on.
Many times I have seen that cover left off after dash/gauge work, it can be easily missed or just plain dismissed during reassembly.
If you were to accidently short one of those two terminals to ground while working on gauges for example, you will get a full B+ battery dump of smoke from your fuse link.
Or if you are quick to remove the short maybe you will get just a curly fuse link.
I knew an 18 year old back in the seventies that got that lesson as a personal experience.
Now that the power distribution circuits are hooked up I can move up the harness to the ignition switch where it will branch out like a tree.
Most of the EEC system is complete but untested at this time. 2-1-2015
DE Mick.