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Wiring back up lights with a catch!

Discussion in 'Truck & Equipment Repair' started by dichdoc, Sep 14, 2006.

  1. dichdoc

    dichdoc Junior Member
    Messages: 27

    I was attempting to wire Auxilary backup lights on to my 78 Bronco with the help of "Alans Wiring diagram" from a search of the site when I discoverd I had NO factory backup lights that work (thats why is was really hard to see!). I finally figured out that the Neutral Safety switch on the auto tranny was not hooked up (back up lights trigger off it as well) The connector on the NSS matches nothing on the truck. It has four wires Red/Blue x2, Black/Red and White/Blue. I managed to find an unused connector on the drivers side firewall (Doesn't match) that has a Black/Red and a White/Blue. The White/Blue has 12v power from the correct fuse.
    Do you think I could connect the WB to WB and wire the Black red to a black red that runs back to the reverse lights to make them work? I would really like lights to come on when I shift into reverse, but I'm nearing my mental limit and am thinking of simply wiring them with a single thro switch.
    sorry for the long confusing post, thanks for your input. Travis
  2. bassfearmee

    bassfearmee Junior Member
    Messages: 7

    back up lights

    oh how I hate wiring problems!.....it is possible that the tranny was replaced at one point, or else it was rebuilt. If this happened chances are the old engage switch was not switched out with the new unit or it ended up with all of the old gears and gaskets that went into the dumpster. The same thing happed to me when I had my tranny rebuilt on my Rodeo. If you can't find a plug somewhere on the housing then you might be out of luck. It is also possible that the switch is somewhere other than the transmission, in which case the mechanic that serviced the tranny might have removed the extention plug between the two connections.\\\Check the wiring diagram on your vehicle, if the switch is located other than the tranny then you might be in luck. Take a multitester under the vehicle with you and test it while the vehicle is in reverse, engine off, key in the power position. Look for a two pronged plug, wire colors wont tell you a thing because they sometimes change between plugs. If you have power while in reverse, you're in luck. Just cut the plugs, wire nut and tape the wires together.
  3. dichdoc

    dichdoc Junior Member
    Messages: 27

    A little up date FYI. I got some help at the Ford Truck Enthusiast Forum and finally located the connector coming from the truck it was on the passenger side firewall and the NSS had been bypassed with a 12 ga jumper and two crimp on ugly bullet connectors. I cut the connector from the tranny and moved it into the engine compartment and extended about 4 feet of wires down to the NSS on the tranny. I had to quit last night and get some new bulbs fuses etc. But hope to have it all hooked up today. Thanks for your help. TB
  4. MickiRig1

    MickiRig1 PlowSite Veteran
    Messages: 3,617

    Ford tends to use parts for many, many years so you will run into replacement parts having a different style plug on them. They also tend to use the same color wires for the same circuits.
    BACK UP CIRCUIT: purple orange wire into switch ( from fuse box ) / black pink to the lights ( out of switch ) This is true from 1980 --> 2000 in my repair manuals.
    If you still don't have back up lights start at the neutral switch and work your way back checking for power to the circuit when it's in reverse ( not running ).
    There should also be a junction plug at the back that tends to have the wires rot off at the plug. One of the harness tie downs will fail and it ends up hanging down and collecting a big ice ball around it causing even more damage.Put dielectric grease on all the connections and the bulbs when you put them in. If you need to take the junction plug out of the circuit make sure you solder the wires together and put the grease on them before you tape them. Try not to use the crimp on wire connectors they fail rather quickly.
    If you still want to add bigger back up lights use a relay. The neutral switch circuit is not designed for that much current.
    Last edited: Sep 19, 2006