How to wire back up light

[33PizzaGuy]

Hello again,

I am finishing up my wiring for my hot rod. I have used the entire RF wiring harness. For the reverse light, there are no wires in the harness. I am using a 700r4 trans with a 383 Stroker. How would I wire this up? Get a light, wire red to +12v switched and the ground wire from the light should go to the neutral safety switch? There are 2 connections on the NSS. Thanks

[33fromSD]

What type of transmission?

Jim

[ggunter]

700r4 Automatic

[edwardb]

I have a 4L65E in my truck build. As I understand, basically a later version of the 700R4 with electronic controls. In my case, I had a +12V reverse gear signal out of the controller. So used that to control a relay (the controller instructions said specifically not to wire the light directly to the signal wire) for the backup light. That doesn't apply to you, but maybe this does: I added a +12V ignition powered wire to the rear harness. I used the radio circuit (no radio installed) but could have been any other suitable ignition circuit. I have it going through the switch (in my case a relay) and then to the backup light. Then have the backup light grounded in place. You'll find some that prefer to switch the ground side. That works too. In that case, run the +12V all the way to the light and the ground through the switch. There were also a discussion in another thread about whether the backup light should be an ignition circuit (only works with the key on) versus a battery circuit (always hot). I don't see a scenario where I'd expect the reverse light to work unless the engine is running. To the best of my knowledge, DD's only work when the key is on, e.g. motor running and transmission in reverse. Most modern cars won't even shift into reverse without the key on and engine running. So for me it's a moot point.

For your specific case, as I understand, those two connections on your NSS (neutral start switch) are neutral and reverse. The should be normally open except when in neutral or reverse. Should be a simple enough manner of running a wire through the appropriate switch to the reverse light. Either +12V or ground, depending on your choice. Also as I understand, the switches on your NSS should be able to handle the current of the light without a relay. Especially if you use an LED backup light.

[J R Jones]

If the transmission has no reverse switch function (seems unlikely) you could fabricate a microswitch mount on your shift linkage. Then weave a 12v wire to the switch and the output back to the lamp(s). Pick the amp rating appropriately or add a relay.

Deviation: Hot wire your brake 12v to the reverse filaments and run the (reverse) ground wire to the shift linkage micro switch. Then you get reverse and brake illumination provided you "ride the brake".
jim

[33PizzaGuy]

Awesome!!!!

[cob427sc]

Not sure what you are using for a shifter but the Lokar shifter has a reverse switch built into the mechanism.

[33PizzaGuy]

I have a Lokar shifter on a 700r4 trans. So the reverse switch you are referring to is the safety switch? I have that and need to know how to wire it . Thank you

[J R Jones]

A shift switch(s) may be contacts for safety (start) in park and neutral. There may be contacts for reverse in that lever position.
jim

[McGuyver]

The switch that came with my Lokar shifter is park and neutral safety switch only, but they do offer a reverse switch set up for your combo.
https://www.speedwaymotors.com/Lokar-BL-1400U-Neutral-Safety-Switch-or-Back-Up-Light-Switch-Kit,43362.html

Or as mentioned, you can fab up your own. Still not sure how I am going to do mine, leaning towards a dash mounted toggle switch that will activate backup camera and reverse lights.

[JimLev]

I used a rocker switch that I mounted in the console.
My Lokar only had a Park/Neutral switch like McGuyver had.

[GlennC]

I just bought a small, but very bright, two wire LED clear light and installed it under the body below the trunk and grounded it. I put a Off/On toggle switch in the dash, ran switched power to it, then ran a wire from the toggle switch to the LED light under the trunk. When I back up I just flip the toggle switch on.