Im wireing all of the lights on my truck and i need help finding where to get power for my backup lights. Im running them on a switch and relay so that i can switch them on or have them come on when i put the truck in reverse. But im not sure which wire to tap into to acomplish this.

 

The existing bak-up light wire can e used to operate a relay by connecting it to pin 85 and grounding pin 86 BUT a new fused Power Wire should be run to the lights. This pwr wire should should run from the battery, have an inline fuse and connect to pin 30, then from pin 87 run to the lights.

Also, a good idea is a ground wire back to the battery from the lights some people will say over-kill and not needed but a battery connected ground wire will reduce ground problems later on.

 

what im doing is using a on-off-on switch running always on power to it and then power from the backup light wire. and then the switch will run the relay. What i need to know is where to tap into the exsisting backup light wires so that i have power only in reverse.

Im putting in a fuse block to to hook all of my relays to and putting fuses between the power sorce and the switch also.

 

Use an On-On SPST Switch… three poles on the backside and the switch can be up for on all the time or down for working with the bak-up sw.

Run a new 12 gauge wire from the relay pin 87 to the new bak-up lights.
Mount the relay near the battery, run a fuse wire from the battery positive post to pin 30 on the relay, then from pin 87 to the lights.
That’s the light circuit now the sw.

Run the OEM Bak-up Light Wire to the cab sw, either the top or bottom pole, with say the switch down and the truck in reverse the current will flow from the bak-up light wire to the switch and out the center pole to the relay (pin 85), then out pin 86 to ground. (adding a low amperage fuse to the OEM bak-up wire before the switch will be a good safety factor)
Same for the straight up power, run a low amperage fused line from the Circuit Panel or some other power location, to the pole that you didn’t use on the switch (either the top or bottom) and out to the relay pin 85 or jump the other wire going to the relay.
The switch will protect any feed back on the wire/switch.

Is that confusing… I get carried away sometimes.

An indicator light can be added to the circuit on either the output of the switch to the relay or the output of the relay pin 87. Of using pin 87 add a very low amperage in-line fuse to be on the safe side. Why an indicator, first I think it would look good and second if in the daytime and the switch is in the ON position for on all the time then the indicator will let you know you might be blinding someone. Also, there are flashing LEDs in different colors so a flashing indicator could be made to work.

Too much, sorry.

 

Wow man thats a lot of info. Not trying to offend you here or anything because you are very knowledgeable and have helped me and several other people out on here but, I know how to wire them. All i need to know is where to get the power from. Where do i tap into the OEM wiring to bring a wire to the switch? Im sure there is a wire somewhere around the transmission i can tap into i just need to know which one. Maybe you answered that and im just over looking it, im not sure. I guess if it comes down to it i can trace the wire back from the tail lights and find a place to hook onto it.

 

No offense taken, I misunderstood what you were asking for.

Is the 98 the same as an 03 ?

 

haha im not really sure about that. i dont know if they changed the wireing when they changed generations or not.

 

bump! i know there are lost of guys on here that have done this. anybodyknow what wire im loooking for?

 

Here is something Bob sent to me, may help.

"Back-Up Light Trigger Wire - rwenzing - Bob

Look in the bundle of wires that drops down from near the center of the dash to run under the carpet on the left side of transmission tunnel. The black/pink in that bundle is the switched hot to the reverse lights”.

After you locate the wire test it out before cutting.
The only other thing if this is not applicable to your truck is find that same bundle of wires in your truck and start probing the wires until you find something to use.

Luck and sorry for any confusion eralier.

 

Thanks! I will check it out and see if i can find it or aleast one that i can use.

 

Consider the “On-On” Sw too, unless you have OEM Unit which I do not.

Pics !

 

I found the black and pink wire under the drivers seat yesterday and thats what im going to use. I almost go everything wired up but ran out of day light. I have pictures of the stuff i built to mount the relays and fuse block on but i havnt built my OHC yet to hold the switchs and CB. so im just going to wire tie them up some where in the cab for now. I would get a ON-ON switch but i already got the ON-off-On one so i will stick with that for now. thanks for the help!

 

How's this working out ?

 

works great so far except i have **** ton of wires just rolled up in front of my shifter.

 

Funny how the little things like clean up take more time than the job itself.

Any pics of your work ?

 

well im not done, the reason i ahve the wires rolled up is because i made sure to have enough wire to reach the OHC that i still have to build so that i wouldnt have splice on with new wires. here are the few pics i have.

the relay mounts before paint.


everything painted.



fues block mounted



relays and fues block test fit before paint

 

I finally took some pics of the wiring inside the cab. my switches were just wire tied around the shifter but they were hard to operate there so i moved them to my CB mic holder since i dont have my cb in the truck right now.

this is where i tapped into the backup lights


and the switches and wires

 

Just updating to put the pics back in the thread.

 

ew

 

I got confused also so I just ran a separate circuit with a simple toggle switch to turn on my aux back up lights so I can use them when I want. I used a switch with the LED in it so at a glance I can see if it is on so as not to offend anyone behind me!