So I really wanna know if its been done…. Has anyone taken a Painless Wiring harness ment for a 1970 mustang and made it work in a 1970 cougar? I already know that the sequential tail lights wont work and thats fine… i have a work around to make them work(currently mine dont work based off the sequential box… they’re an leds on a board that have the sequential feature built into it)
Pic of my led tail lights for those who are curious
But besides that will it just plugnplay? Will the gauges just work? Same for everything other than the sequential tail lights…. Obviously wire length will also be different but I really wanna know everyone’s opinion
There are couple of issues I can think of, though they may be minor. The Mustang uses a single rear bulb which function-wise, would be similar to the cougar without the sequencer box (you would only have the inboard lights on each side working). The rear side marker lights are driven out of the sequencer box on the 70, so they may not work with the Mustang harness. Also, the sequencer uses a direct input feed from the brake lights so the sequence doesn’t activate when you apply the brakes. If your kit built-in sequencer doesn’t have that function, your lights may sequence the first time you hit the brakes. I have seen that with other LED kits and don’t care for it , but that’s a matter of preference.
The thing is my custom tail lights only use the socket for one bulb so the 3 individual bulbs really wouldnt make a difference… and the kit has a single pink wire that runs separate from the harness to know when its just the break lights and when its the turn signals
There is nothing about the turn signal system that is the same. Charging system wiring is different. A base Cougar is closer to a Mustang. No Mustang was ever wired like the XR7.
The funny thing is that the people that know the least about 12 volt electronics are the most likely to yank the factory harness and try to start over. Given that why don’t you do it and then create a build thread so people can see how it is done.
Fortunately for me I’ve got a base cougar… but i definitely am looking into options but i really don’t wanna go through the pain of building a harness…. Im more of a mechanical guy than an electrical guy… some things just make more sense to me and the last thing i want is to burn it down because im an idiot and over look something …. And id also like to get it done in a weekend or less so the car isnt down for too long
I bought repoduction front turn signals for my 68 XR7 pluged them in to my front harness almost burnt out the wiring as it started smoking. I unpluged it before it totally burnt up.
Just saying that the mustang & Cougar are simular but not quite the same.
Woah man im happy it didnt burn the car down!!! But i figure replacing the whole harness shouldnt give me any issues… at least thats why im here to figure out
I’ve been in 12 volt electronics professionally since 1973. I would allow at least 40 hours to rewire a car. You will need to make hundreds of connections and they all need to be perfect. You are far better off getting the original harness rebuilt and then using sub harnesses to power add ons.
I don’t know about hundreds of connections…But, I used Auto Meter gauges, basically its a GM style wiring. Its definitely a good idea to have an original schematic with color codes because some wire colors are different. I actually find it very simple compared to the original wiring. IMO, but I am partial in knowledge to GM.
Welcome to the CCC Forum. Are there issues with the original wiring harness from your 70 Cougar that are beyond repair? I have an extra decent Standard 70 Cougar dash harness available that could be easily shipped to you.
Here’s a link to photos of the wiring harness: 70 Cougar Std Dash Wiring Harness
You are welcome to contact me with any questions that you might have. Thanks.
Rather than beat yourself silly trying to make something fit, send your harness to Randy at Midlife Harness Restorations. He can add/subtract options to make your harness custom to your car and the wiring and color codes will match the OEM schematics. http://midlifeharness.com/
Just a suggestion… Why not ask Painless if you can send them your harness and have them just make a duplicate. That’s what they do is make wiring harnesses. It ain’t rocket science…
Also if they don’t already make a correct harness, if you send them one, then they will have the pattern to make more…
Gauges must match senders. Ford gauges are designed to operate on 5 volts. The amount of power in the circuit is less than half of what a 12 volt gauge would see. You need to use senders that are 12 volt devices if you are using 12 volt gauges
First question is why do you want to replace the entire harness? Is it such poor shape that it can not be reused or repaired? I too am in agreement you would be better off using the OEM harness rather then the painless mustang version. Cougar to Mustang is just different enough to cause you more headaches with an aftermarket harness if your not familiar with those differences. It will not be a “painless” install thats for sure and will require modifying to fit your cougar.
I suggest using your OEM harness if possible and building your own additional harness for aftermarket accessories if so desired. This way you separate add ons from the OEM harness and do not risk overloading circuits.
but i definitely am looking into options but i really don’t wanna go through the pain of building a harness…. Im more of a mechanical guy than an electrical guy… some things just make more sense to me and the last thing i want is to burn it down because im an idiot and over look something …. And id also like to get it done in a weekend or less so the car isnt down for too long