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Oct 4, 2016
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Location
preston,iowa
My Car
72 mustang convertible.351c 4v bored and stroked,roller cam and lifters,still in process of restoration
[url=https://ibb.co/JkTyQV2][img]https://i.ibb.co/0JLFtTZ/MUSTANG25.jpg[/img][/url]
Ok, I have a 72 convertible I bought as a project in pieces, I have put a Cleveland in it and trying to figure out some wiring in the engine compartment, I have a plug, at the fire wall that has 4 wires coming out black with white dots, red with white stripe, red with green stripe and red with what looks like yellow stripe .i believe one is the temp light but not sure on the rest or where they go, im not very good at electric scheumatics and cant seem to figure them out, I also have the wo wires coming from the brakes into a plug, one brown wire and one red wire but then come off the other end of the plug as only one red wire,if I hook this red wire to anything the brake light comes on, where does this go?

 
OK -- I'd be real careful here..  When I was circuit chasing in my 71 some reds and yellows looked more like browns etc. 

we don't want a sudden under-hood fire as some may be services going to the hot side of your fuse panel .  have look through this link ... https://www.7173mustangs.com/images/1971_full.pdf  

My advice is first put yourself into a position of knowledge  ....Get a multi-meter (Volt meter) and see if any of them are hot compared to chassis when key is in first position

You could - if unsure (need a friend reading the meter of this) - lift one side of each fuse - if the volts disappear you know which fuse is carrying that service. 

Red and white on mine is Temp light



Does your circuit have the tachometer?

all the best 

Al

 
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Ok, I have a 72 convertible I bought as a project in pieces, I have put a Cleveland in it and trying to figure out some wiring in the engine compartment, I have a plug, at the fire wall that has 4 wires coming out black with white dots, red with white stripe, red with green stripe and red with what looks like yellow stripe .i believe one is the temp light but not sure on the rest or where they go, im not very good at electric scheumatics and cant seem to figure them out, I also have the wo wires coming from the brakes into a plug, one brown wire and one red wire but then come off the other end of the plug as only one red wire,if I hook this red wire to anything the brake light comes on, where does this go?
Ford used different wiring harnesses for the different engines, as the sensor locations change. Here's the correct engine harness for a 71 w/351C. It plugs into the connector by the brake booster/master cylinder. 

http://www.mustangsunlimited.com/Mustang/Ignition-Electrical/Wiring-Harnesses/Engine/Engine-Gauge-Feed-Harness-1972-351C-2V-CJ-HO-Mustang-Cougar.axd

Red/lt green stripe - coil (+)

White/red - oil pressure sender (behind intake)

Red/white stripe - temp sender (pass frt block by water outlet)

Red/yellow stripe - throttle position solenoid on carb

The black wire could be for A/C clutch, or an emissions wire. clean it up really well to see what it is. Could be black w/yellow hash (A/C) or Brown w/yellow dots (emissions solenoid)

Post a pic of the brake wire, I don't see anything in the diagram like that.

1972_full.pdf

 

Attachments

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That plug is not for brake distribution valve; that is on top of the distribution valve and has two violet/white wires.

Note that one side of the plug in question has only one wire; the other side has two wires/ two pins. No idea what that wire goes to. I believe the two wire pin is for emissions of some type.

 
By brake light do you mean the brake warning light on the dash or the brake lights at the rear of the car? Brown wires are for the taillights and the side marker lights.

The red wire looks like it has yellow dots or yellow hash marks???

It looks like someone has been probing the wires a lot. To keep the copper wire from corroding I would get some liquid tape and cover the probe holes.

Is the 4-wire connector in the picture the one you're referring to? If so, it looks like a black with yellow hash marks, which would be for the power window relay.

It's hard to see what colors some of these are after nearly 50 years of being exposed to the elements. WD40 works pretty well at cleaning them without wiping off the stripes.

 
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The four pin flat plug is your engine gauge feed plug: oil, water, coil, and carb anti-stall control. The picture is from the engine compartment.

 
it sound like I should add some info on car? this is a non air and no power windows or locks, its a pretty bar bones car from the factory. I added a new HEI distributor so there is no external coil anymore. this is what I have so far.

four wire plug:

red with tl green stripe I have connected to my hei for constant 12v to power it.

red with white stripe, temp sensor

white with red stripe: oil pressure sensor

black with yellow dots: no idea.

now the two wire plug im still stumped on, there is one red wire and one brown wire going in but only one red wire coming out, there is no volts to it with the key on or off..

 
The red with light green stripe wire will not supply 12 volts to your HEI, it will only supply around 8 volts, it is connected to the resistor wire, which is between the ignition switch and firewall.

Did you read my post above (#4)? Verify if the red wire has yellow dots or hashes.

What transmission do you have?

 
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Thanks for the help.her is a picture of plug in for brake light

Being an electronic designer for Lear Corp. the chunks taken out of the insulation bother me. ... because a short with continuous current (DC) causes heat.... heat = fire ....fire = car turned into a crisp 

My OCD can't cope with this image.

 
four wire plug:

red with tl green stripe I have connected to my hei for constant 12v to power it.

red with white stripe, temp sensor

white with red stripe: oil pressure sensor

black with yellow dots:  no idea.
The red wire with lite green stripe in the stock wiring is reduced voltage through the resistor wire, so not really 12 volts unless resistor is bypassed.

As shown in the 1972_full.pdf diagram, page 7, BK-Y(H) wire 347, connector C-14, goes to air conditioner clutch solenoid. Think this  wire is in the harness even if you don't have air.

 
take all your wiring out, send it to midlife, try to remember where it goes when it comes back.

 
take all your wiring out, send it to midlife, try to remember where it goes when it comes back.
I'm temporarily out of business while my house and garage get refurbished due to a Michael accident.  I hope to be back working late this year.

 
Don, it looks like the red wire has hash marks not dots. And trans in an fmx. As for the horrible shape of wires, the good thing it the damage seems to all be after the plugs so I will be in search for new wire harnesses after the plugs, I have a couple of parts cars that may have them on there that I know are sitting in fields with no engines in them. I just need to get over there and see if they are in better shape.

 
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