Painless 20120 Harness Installation

Discussion in 'Classic Mustang Specific Tech' started by geordie, Mar 24, 2008.


  1. Rusty67

    Rusty67 Well-Known Member

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    Ed, remember that a daily driver car in LA, or another metropolatin city, may very well see enough idle time to cause a problem when using a true 1 wire alternator. This is why I always recomend the 3G.
  2. Hack

    Hack Active Member

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    I have a 3G in my '70 and I love it. I highly recommend using a 3G in any project car. I got the wiring bits from PA Performance - they are great IMO. :nice:
  3. lauras70mach1

    lauras70mach1 Member

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    The way I understand it is 1-wire alternators begin charging at a certain rpm then, once energized, charge at idle no problem. This is how my diesel truck works anyway.

    As for the race car comment, a lot of serious race cars don't even use an alternator, they just use the battery.
  4. Edbert

    Edbert Founding Member

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    Understood, I used a 67 Stang as my DD from 1982 until 1993 or so.

    Here in StangNet we've spent so much time and discussion on resto-mods with 400+ HP that I always forget that there are folks who still do

    :flag:
  5. geordie

    geordie Founding Member

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    I'm back on the Painless wire harness installation. I can't believe that I've been on this project, off and on, for almost a year. Painless it is not! So far I have the engine section, under dash and tail section installed in the car. Working from the front of the car, the headlights and turn signals are wired up. The main looms are routed in the engine bay. The engine is out of the car so I will complete the under hood wiring when the engine is installed. Under the dash, the harness is connected to the under hood looms and routed under the dash, the steering column is connected. The cigarette lighter is wired :rlaugh:(big deal), I'm working the remaining switches. The tail section is routed through the car into the trunk. The whole harness has been wrapped with Painless Power Braid. I'll post some photo's over the weekend.
    I've basically given up watching the TV over lent so that I can get out in the garage over the next three or four weeks to get this wiring done.
  6. geordie

    geordie Founding Member

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    I got my ignition switch wired in last night :D. A couple of things to bear in mind.
    a. Clean off nay flash from the underside of the bezel. The first time I went to install the ignition switch, the new bezel scratched up my dash and I had to repaint.
    b. Despite following all the instructions I had, I missed the point that the switch and bezel need to be orientated correctly for the lock barrel to engage correctly. Another hour wasted trying to figure that one out. I'll post photos soon.

    On to the wiper switch now.
    I have an aftermarket single speed wiper switch with washer pump option. The painless instructions say that I have to connect one lead #969 (I think) to the wiper motor. My wiper motor has a connector with 3 contact and one separate contact on the case, a ground I think. Does anyone know where this #969 lead needs to be connected to:shrug:. I'm going to e-mail Painless as well.
  7. CraigMBA

    CraigMBA New Member

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    Setting up the 3g to operate 1 wire is perfectly OK IMO.
  8. Rusty67

    Rusty67 Well-Known Member

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    Craig, a 3G and a GM type 1 wire don't operate the same even if you don't hook up the other wires in the 3G.
  9. geordie

    geordie Founding Member

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    Pictures of ignition switch and bezel correct orientation attached.
    Has a good weekend this weekend, rebuilt the heater controls with new cables and fascia and knobs. Installed it. Put in ashtray rail, checked for wiring clearance, under and around the ashtray. Wired up the brake switch and routed and secured the wires. Secured the trunk wiring about the drivers side sill.

    Still puzzled about the washer wiring...........
    Waiting for some courtesy lamp holders, nobody makes replacement so I've found something online I think will work.
    Need some more T56 connectors, waiting for them to arrive.
    T56 crimpers are $100+, will have to use needle nose and solder.
    Got new gauge pod housing and lens, am going to start work on that.
    More pictures to follow.

    Attached Files:

  10. geordie

    geordie Founding Member

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    Another image attached

    Attached Files:

  11. geordie

    geordie Founding Member

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    I took a look at the car at the weekend.
    Under the dash I have the two wires #968 and #969. I have two spare terminals on the single speed wiper switch with washer control. Under the hood I have the same wires #968 and #969 close to the washer location.

    The original 65 Mustang wiring diagram shows the washer grounded to the chassis and a single wire from the switch. I understand this but cannot reconcile it with the Painless wiring.

    For the 20120 harness I would really like a good sketch or explanation of how I connect up these wires #968 and #969. Can anyone help me out. By the way I am not naturally electrically savvy.
  12. geordie

    geordie Founding Member

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    The advice I got from Painless was that this harness is set-up for different year model Mustangs with different systems, I need to use the #968 and under the hood the #968 attaches to the washer, and not use the #969.

    I'll try and get the wiper switch installed this weekend.

    Also I've dismantled the instrument pod. I'm going to repaint the sheet metal gauge surround, it was a bit beat up. Other than than should be ok. Will clean it up a bit. I'm wrapping the harness that connects to the gauge pod.

    Must try and post some pictures for you guys.

    I'm getting excited, dash is nearly done, then on the the trunk. :)
  13. 1966conv

    1966conv New Member

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    I've read this and have my own opinions about the painless kit. I realize that you use a universal versus a "oem replacement".

    I used the oem style in a 68 and I can say it was not painless either. I've replace harnesses in 66's twice, both taking a weekend. The 68 painless "OEM" took me in the neighborhood of 70 to 80 hours over three weeks. I definately learned much about the mustangs electrical systems. On a cost analysis basis, paying myself at minimal labor, it was not worth the cost of not buying new harnesses. (except for what its save as stress reduction.

    BTW even the OEM replacements still need to be wrapped.

    The main problem I also had was figuring out if I needed a ground when something did not work.
  14. geordie

    geordie Founding Member

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    This weekend I (almost) completed wrapping the small harness behind the instrument pod. The painless kit includes seperate pigtails for some of the small lights and the gauges. You have to pick and choose some depending on your instrument cluster.
    I never want to see another zip tie as long as I live.
    I've bought a new instrument surround and lens. There's a thin sheet metal sheet between the lens and the instrument bucket. Mine was original and beaten up. The PO had obviously been at it. I had to massage some of the bumps and am in the process of repainting it.
    See attached photos.

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  15. geordie

    geordie Founding Member

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    More photos of plate. I've painted the white side and need to paint the other side black and mask off the other black portions.

    Attached Files:

  16. alexb_

    alexb_ New Member

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    Does the kit come with those labels or did you add those yourself? That's a good idea.
  17. geordie

    geordie Founding Member

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    Many of the wire bundles are labeled, but when you wrap the bundles you loose the labels and have to find some way to re-identify them. Sticky tape and a marker would suffice but I like making more work for myself. Masochist.
  18. geordie

    geordie Founding Member

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    Progress report, made a pods of painting the sheet metal plate behind the dash lens. Had to strip it and am in the process of repainting it. Installed the wiper switch, was able to use the old switch 'bake a lite' plug from the old harness. Per the instructions from Painless I did not connect the #969 wire, instead I capped it off. Will use the #968 wire to power the washer motor, the motor is grounded to the chassis. Also got the courtesy lights installed, see separate thread. Need to think about the emergency flasher switch. Will start another thread about that.
  19. golf4283

    golf4283 Active Member

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    Not to Hijack the thread but I'm gonna start my Painless 20120 install tonight and have a few questions that hopefully someone electrically inclinced can help with.

    1) I upgraded to a 3G alternator and don't know how to properly wire it.

    2) I am wondering if I can replace the Amp gauge with a voltmeter and still connect everything the same.
  20. Tim65GT

    Tim65GT Active Member

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    Here is a diagram on the 3G.

    Current for a ampmeter goes through it. You would have to tie the leads together to bypass it.

    A voltmeter simply ties into a "key on" source and the other side is grounded.

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