1970 Sport light wiring questions

[tmunn]

What would I be looking for under the dash to verify if i have the sport light wiring harness and the wires to the switch.My switch was removed from the hole in the dash and i "think" and hope they used the wires for a electric fan switch that had temporarily relocted as opposed to just cutting the wires like they had.If the wires i need are there and I can re-use them that would be great .
I have two wires comming out of a two pin trailer type connector and will check on their colorr tonight and take a picture.One was just cut off and the other had a connetor on it that went to aline lock switch on the shifter The switch and line lock control will be eventually removed.Not my style....

The plugs for the lights at the rad are not there either but they could have been cut and are in a harness or taped up somewhere I will be checking further out there at a later date.

[Blues Power]

i dont mean to sound like a butt head but dude what in the world did you buy with all these wiring issues. as I mentioned previouly you need to buy the schmatic booklet for $10.

theyre not that hard to read. basccialy yuo find what you need fixed and follow the wire to where it goes with your finger

for your question the SL will have a 3 pin connector close to where the hole is for the switch.

if you want the SL page pm me and i will send it to you

[tmunn]

AHHH no problem.I bought a car that has been taken apart and the put back together but not correctly and some parts missing.I have printed an on line version of the wiring diagram and will try and figure it out.If the parts were there atleast,,,,I think i could figure it out.electrical stuff will be my bigest challenge I think.
The care is VERY sound but needs lots of small things and i want to know what does what etc...

[tmunn]

Well i had a friend visit tonight and i put him to work.He is good on electrical for sure.We took a printout of some on line schematics for a 70 mach one/grande we found on line and used them to trace back some wires to the firewall and the drawings showed 9 solid lines indicating wires that would be there for sure and 2 more dotted lines indicating 11 for cars equiped for sport lamp(which mine has)going into the connector at the firewall if the car has SL's which mine does. .I started at the lights and unwrapped all the wires back to the firewall and ended up taking the fuse box off and the plastic connector out of the firewall.I am missing the Gray wire and the green and yellow and we checked the pin location in the female side of the green box and the pins are missing there as well so there are no wires under the dash for the SL's.The vin indicates it's a mach one and everything matched the marti report at one time from what i can tell .

Does anyone have any idea what might have happened.The car was totally taken apart by someone and maybe they replaced the wiring harness with one from a non mach 1 car but it would have had to been inside harness and firewall to lights, which is possible as my car has had a lot of things changed .

What do you guys think may have happened ? and how can i make it right.My buddy says I should buy the 11 wire harness and we can add the two pins and wires to the female side of the block and go from the SL switch to the double black connection on the switch.

Are we missing something.The wires are just not there.HELP

[buening]

Sounds like the underdash harness must have been swapped out at some point. You looked at the harness right above the radio area for the sport lamp connector? It'd be obvious it if was there. It isn't a common connector, so unless you find a junk harness with that connector you may be SOL. May have to keep an eye out on ebay for a mach underdash harness, and keep in mind there are multiple configurations depending on tachometer or non-tach, a/c or non-a/c, mach or non-mach, and keep in mind the 70 harness is different than the 69

[tmunn]

I agree that the harness may have been switched out.Do you think the same for the headlight harness.The drawings said we should have 11 wires going into the plug at FW and we only had 9.
Could i not make a little harness of three wires and go to the coresponding female pins in the green block and then to the double black in the light switch. it's getting late so i will have my buddy check on that prospect when I see him again.
I could figure away to get the wires connected to the switch if i have to but in the mean time i know where there might be a harness I could check next week

[tmunn]

Update, i called Virginia mustangs an he compared the two wiring harnesses they sell from AMP and the pre10/15/69 for sport lights has 11 wires in it and the post 10/15/69 has only 10 wires.

My car was produced feb 25 1970 so i should require the 10 wire harness, but according to the drawing i am using(maybe it is for pre10/15/69)shows a gray wire and a green yellow coming from the firewall connector out to the sport lights.
mine is obviously wrong as i have only 9 wires and pins total going to the male side of the green block and comming out of the green block.

Would the 10 wire harness work thus eliminating replacing one of the missing wires from the female side of the green plug going to the switch.
That does not make sense because the switch has 3 teminals and the drawings show 3 wires going to it.
My drawings show three wires coming off the switch.Two to the green plug getting connected at the plug then and travelling in the harness out to the plugs for the sport lights and the other one to a black coming off the light switch. that is how i understand it.

[Alan _MacDougall]

I have the pre 10/15/69 harness's in my Mach1. I replaced all my harness's with Alloy Metal Products. I found them to be an exact replacement. Dallas mustang sent me the post 10/15 harness and I had to send it back for the pre 10/15 harness. As I remember the pre 10/15 front exterior light harness's has extra ground wires for the sport lamps in it. If I were you I would purchase the correct AMP underdash harness and front light harness.

[miketyler]

The sport lamp switch has three pins indeed but the plastic plug it plugs into only has two wires coming off of it, a grey and a black one. Sounds like your headlight harness has been butchered. I agree with Alan on this one and would simply replace the headlight harness with the AlloyMetals product. Its concours level correct and even has the fluid hose taped in for the windshield washer bottle.

I pulled all the wiring out of my car and had Midlife refurb the rear and underdash wiring. Being draped inside the engine bay the headlight harness takes the most abuse from engine heat to picking up water from the front grille. It can be had fairly cheap and all you would have to wire in then would possibly be the switch.

[tmunn]

Thanks guys .alan and mike when were your cars produced and mike which harness did you get.The drawings clearly show a green yellow wire on each side of the firewall plug making me think i need the 11 wire then i check my mfg date and cross ref that and i should have the 10 wire and after what allan said about the switch only needing the gray and black reminds me of what i read somewhere about them splicing a wire in the post 10/15 harness and eliminating a wire.Maybe they eliminated the Green Yellow.... My elecrical skills are fair on the best of days.
Which one should I order ?

Oh yeah i have been forgetting to ask.Is the new harness still the best rout to go if i want to install headlight relays as well or will i just have to take it apart to install heavier wires for the headlights.I have been reading about it some and they suggest 12ga wire from what i can understand.

[Alan _MacDougall]

Mine was made on 10/7/69. Heading out, I'll post more later. The changes were in the headlight harness not the main harness. They simplified the wiring (reduce manufacturing cost) to the sport lamps. I Remember comparing the harness's and wondered why they wired the pre 10/15 harness like that.

[miketyler]

I wasnt aware of the difference in early or late production year. When I bought mine I thought there was "with sport lamps" and "without sport lamps"

On the CJP site, Rick Peraino, a CJP customer left this feedback for potential buyers looking at the AlloyMetals headlight harness. From his review:

"Make sure you know the build date of your car, or better yet, remove the old harness and count the the wires before ordering the new harness. When the 1970 models were first built, the front, under bumper parking lights were wired on a separate circuit from the side marker lights. Ford made a wiring change in the fall of 1969 and put all the parking lights on the same wire, eliminating one wire from the underhood/headlight harness. The reproduction harness for Mach 1's built after 10/15/69 only has 10 wires, the early harness has 11. An early harness will not power the front parking lights in a late car, but the late model harness will work in to power all the parking lights in all 1970 Mach 1's. The early harness disabled the front parking lights when the sportlamps were turned on."

70HLWL Mustang Headlight Wiring Harness With Sport Lamps From Firewall 1970 | CJ Pony Parts

[tmunn]

Thanks mike i read that on cjpony parts as well.Does that not go against what alan had posted. his car is pre10/15 69 and he had to send the one for a newer car back and get the older one 11 pins. If i read this correctly the newer 10 wire harness should have worked for all 70 mach 1's.
I would say if i don't have any under the dash wiring now that it would seem reasonable that i should be able to get the 10 wire for later production cars and run a gray from the switch to the gray in the block and run a black from the switch to the double black in the light switch as shown in the drawings thus eliminating the need for a green yellow wire which Mike says is not on his switch harness or switch.

This seems overly complicated or am i just slow.it will be a big hassle for me to get the wrong one and now is the time to make it right since the car looks like this.
Do you think the wiring foor the switch is as simple as from the switch gray to gray and black to the HL switch or more complicated than that ?

Thanks for your patince guys i think this whould be the most challenging electrical issue i will have .I don't want to change out the unde dash because mine is in very good condition just missing some wires is all.
I could use the money for other parts of the car.

[miketyler]

Maybe Alan wanted to keep his car all correct with matching 11pin headlight harness? I will have to check my build date now. I stil have my old headlight harness I guess I could count wires but honestly, I am inclined to believe the post that the later build date 10-wire works on all 70 Mach1's. This might explain why most parts houses only carry the two harnesses; one with and one without sportlamps and pay no mind to the early and late production dates

[wantaboss]

The way I read the electrical diagram the switch has a green/yellow a grey and a black the black goes to the automatic shifter light socket the grey goes from the switch to the sport lamps carrying the power to the lamps the green and yellow is supplying the switch with power from the front turn signal/ marker lights and the sport lamp light socket is the ground so at the switch you should have a black green/yellow and grey hope that helps I also had to replace the whole harness under the hood PO had the wrong one in and the harness was all spliced into to make the sportlamps work