• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

Off road light wiring issue and Name this electrical pigtail


Tractor Dan

Well-Known Member
Joined
Dec 29, 2008
Messages
297
City
Near Lima, Ohio
Vehicle Year
1994
Transmission
Manual
Ok. First question which is most important is this. I have two 6 inch off road lights on my front bumper running 55w h3 bulbs. So total of 110Watts. I replaced both bulbs and redone the wiring. When i put them on i didn't pay attention and the wiring harness that came with the lights had either 16 or 14 awg. I upped that to 12 awg. So running 12 awg wire in the hole set up. Other then the ground wire which is the 14 or 16.

I currently have the lights grounded to my steel license plate bracket on the bumper. The power wires currently come together with a wire coming off the switch and all three are joined with a 12 gauge wire nut. From the switch out to the battery i have a run of 12 gauge wire. It is fused with a 15 amp fuse inline. So here is the issue. My passenger side light comes on and reads the full 12 volts. The drivers side off road light however does not and reads around 6 volts. I'm lost here because if the wires are joined with the same lead wire i would think they would be getting the same voltage at each light. :icon_confused: So what do yall think i have going on? I'm guessing it has to do with high resistance on that one light maybe? The thing is this worked before i rewired and replaced the bulbs. Both lit up fine. Until one burnt out from age. It was a couple years old.

I'm gonna attach a picture. It's a crude drawing of how i have them wired but it works. Also the second picture will be of the mystery pigtail. I was under the truck grabbing a screwdriver that fell and i look up and see this at the front. Right near the end of the frame rail. I'm wondering if it's possibly a wiring harness connection for fog lights even though my truck doesn't have them or a switch for them. :dunno:

offroadlightwiring_zpseb7ffad6.jpg


20130218_162855_zpsf81569a2.jpg
 
If everything on the truck is working normally in regards to that connector? It's probably not used and can be ignored. Wiring harnesses are universal and have plugs and cables run for every option--even the ones you didn't purchase and didn't have installed. But it's cheaper for the company to use a fully loaded harness then start producing several different types depending on option packages.

S-
 
If everything on the truck is working normally in regards to that connector? It's probably not used and can be ignored. Wiring harnesses are universal and have plugs and cables run for every option--even the ones you didn't purchase and didn't have installed. But it's cheaper for the company to use a fully loaded harness then start producing several different types depending on option packages.

S-

:dunno:
 
Thanks for the input. Think i'm gonna go the relay route. It might have to wait till April or May. I go in for hip surgery March 4th and i will not be driving anything for a while. Well unless crutches count as a vehicle. I wired those in 2010 that way and never had an issue. I was gonna do a relay then but money was so tight that i couldn't afford one. They wouldn't have got wired or mounted had my friend not let me borrow wire and use his welder for the mounts the lamps bolt to. So we done it and it worked so i never got around to the relay. I really don't use them all that much. Other then if i'm on a back road i kick them on or if i see a car on the side of the road and stop. Those come in handy helping someone change a tire. Thinking of mounting a couple work lights on my back bumper that swivel. So looks like it's the relay route down the road. I was wanting the truck buttoned up before surgery but it's drivable so that's what matter incase my parents need to use it to move.

As for the wiring harness i figured that was the case. Just never noticed that connector so i'm like hmmm what could it go to.

Thanks again for the input everybody. Quick question limabean. Does your screen name have a specific meaning? I live near Lima ohio and we have the Lima Bean as our town mascot. So i'm like hmmm maybe a former ohioan? I know your profile says you are in another state.
 
That plug looks like it is probably for fog lights. Especially if it is near the front bumper.
 
Might I recommend that when you rewire get your switch power from an accessory circuit instead of the battery. That way you can't accidentally leave the switch on when you turn off the truck, but will be usable in accessory or run position.

I'd go so far as to recommend disconnecting the lights until you can get them on a relay. Better safe than sorry IMO.

As for Lima's screen name I seem to recall it being related to the engine.
 
First rewire as suggested, always good to start fresh and always use a fuse and relay for the main power wire.
Second yes use a relay but use your parking light circuit to trip the relay and add a switch to override it if necessary.

Also, grounding, one of the most important part of the light circuit.
12-ga power wire is great but you should always use the same size wire for ground as for power AND run the grounds back to the battery area, either to the negative post of the battery or a grounding stud, mounted near the battery and that is attached to the negative post. Ground wires run to the bumper can cause a lot of electrical problems.

This schematics is a basic light hookup with a dash-switch, get them in working this way or replace the switch with a wire to the Parking Lights.

_AuxLightSchematic-PinNo87AAmperageInfo.jpg


Here is the write up I did for another Ranger Forum, it is a long read but should be helpful for rewiring.

The schematic will work with either Off-Road, Back-Up, Headlights or any Auxiliary Lighting can be hooked up with slight variations on this schematics.
All grounds are grounded back to a terminal strip or stud not to the body or frame, this will reduce electrical problems from poor grounding through rubber mounts, rust, corrosion, paint and grease.

What you will need:

- Relay(s) – 30-amp Automotive Four Pin Relay, pins numbered 85, 86, 87, and 30. If you have a relay that has pin 87a, this will work but be aware that pin 87a will be live with Battery Power when the lights are off; this is good if you are getting creative but not so if a wire or a tool hits it and things start to short out.
- 10-ga Automotive Wire – Do-Not use Household Wire, that is found at the local Hardware Store, for automotive wiring. Buy enough Wire to run from the battery to where you want to mount the relays then on to the Lights; no real min or max on this wire length, it will all be considered short runs.
- 16-ga Automotive Wire – buy enough to go from the inside Circuit panel to where you want to mount your switch, then to the relay under the hood.
- Dash Switch – This is to control the Relay with a low amperage circuit, the switch should be capable of handling 12 volts minimum; a 125 or 250-volt switch will work if it is the type you want. There are too many different types of switches to mention here but for the easiest type and related to the schematic buy a SPST (Single Pole Single Throw) (On-Off) switch.
- Fuse Tap - A connector to tap a Circuit on the Circuit Panel inside of your vehicle.
-Fuse Holders – Two in-line fuse holders, one for a low amperage fuse (2 amps), for16-ga wire and one for a high amperage fuse (30 or 40 amps) for 10-ga wire
- Fuses – One 2-amp for the Switch/Relay Circuit and one higher amperage fused based on the total current draw of the Main power, i.e. 2, 100 watt lights = 200 watt / 12 volts = 16+ amps, you will need a 25 or 30 amp fuse for the lights.
The Fuse Holders can be the older Barrel glass Fuse or the newer Blade Type, your call.

NOTES:

Activating Relay – Pin 85 on the Relay is used to activate it and 86 is used for the ground but both wires are required to make the Relay work. Some Relays without pin 85 but they ground through the mounting hardware. It is a good idea to ground close to the battery or directly to the negative post on the battery. (Pins 85 and 86 are interchangeable)

Main Power from Battery - Use a minimum of a fused 12-ga wire from the battery to pin 30 and from pin 87 to the lights when hooking up 2 - 100 watt lights. It is better to use a heavier gauge wire than a smaller gauge wire, i.e. 10-ga instead of 12-ga. In my opinion there is no such thing as over kill when wiring high current in a vehicle, bigger is better.

Fuses – The fuse is there to protect the circuit and all of the components in the circuit and needs to be rated for the smallest component in the circuit plus a small margin for initial draw. MAKE SURE TO USE FUSES.

The Install – (Everyone does things a little differently but this is how I do it and it has worked fine for many installs)

Step 1) Mount the Relay under the hood and the Dash Switch where you want them.

Step 2) Using a DC Electrical Probe or Multimeter find the power type you want to control the Relay via the Dash Switch.
a) On all of the time, so the Dash Switch will do the main power control
b) On with the key, so the power will be controlled by the ignition via the Dash Switch.

Hooking up the Switch with a low amperage circuit:

Step 3) Run a 16-ga wire from the power point on the Circuit Panel (Step 2) to one pin on the switch.
Note: Usually there are two pins on a SPST Sw, sometimes there are three pins; it is suggested to use the two pin type of SPST Switch.
Two pin switches are on/off devices and any wire can go to either pin.
Three pin Switches are on/on devices; although they can be used for on/off the extra pin will be live when the lights are off. If you use this type of switch make sure to insulate the extra pin.

Step 4) From the second pin on the switch run two wires, one will go to pin 86 on the Relay and the second wire will go to the power side of the Indicator Light.
Note: Some Switches come with indicator Lights inside of them and all that is usually needed is an additional wire to ground but everyone is a little different so double check what connection on the switch do what and hook up accordingly.

Step 5) Hook up the Ground of the Indicator Light – Most DC lights have two wires, one power coming from the switch and the second is the ground and the ground needs to be connected to a good metal grounded point on the body of the vehicle.

Step 6) Connect the Wire from the Switch (Step 4) to pin 86 on the Relay.

Step 7) Run a 16-ga wire from pin 85 to ground, use some external tooth star washers on the connection to make sure the connection makes contact with new metal.
Note: I like to use a Conductive Contact Paste on the ground connection to keep things cleaner longer.


Test Point…

Step 8) At this point you should be able to flip the Dash Switch and hear the Relay click, if you don’t hear the clicking re-check all of the connections or if you hooked up power to the switch as a Key–On Power only, then turn on the key. Once you hear the Relay clicking then you are ready to hook up the power to run the lights.

Hooking up Battery Power to run the lights:

Step 9) Run a heavy gauge wire from the battery positive post to Pin 30 on the Relay, make sure to have the higher amperage fuse in-line with this wire.
Note: Mount the fuse close to the battery, this is a safety link and should blow out as first sign of rising heat in the line (a shorted circuit that is).

Step 10) Run a heavy gauge wire from the Relay, pin 87, to the first light and over to the second light. Allowing for routing the wire and connecting the wire to the second light.

Step 11) Make the connection to the first light - To make a connection, strip some of the sheathing (outside covering) off of the power wire, make sure NOT to nick the wire. Wrap the Light Wire around the Power Wire (as flat as possible – do not tin before soldering) and solder this connection. Clean it and slip a piece of Heat Shrink with adhesive inside, on to the power wire but do not shrink it at this time just slide it over the joint. (Note: When attaching the Light Wire to the Power Wire, allow for heat Shrink Application either before or after soldering, watch the direction of the two wires)

Step 13) Make the connection to the second light - Run the wire from the first light to the second, making sure to slide a second piece of Heat Shrink on the wire. Cut the wire to length, solder the connections and clean them, again do not shrink the Heat Shrink just slide it over the joint.

Step 14) Grounding the Lights – You can ground them to the closest metal that will allow you to secure or you can do it the way I do. Run an additional wire, the same gauge as the power wire, from the Lights to the negative side of the battery or a grounding point near the battery that will be connected to the battery. Attach by preparing the wire and soldering the same as the Power Wire and don’t forget the heat shrink. Note: By running a separate Ground Wire back to the Battery you will reduce the main reason for Lighting Problems – POOR GROUNDING and in turn allow the lights to burn at their brightest and burn longer!

Test Point…
Flip the switch and the lights should come on. If they don’t you will need to re-check the Power Wire only from the battery to the Relay and then from the Relay to the lights; that is if the Relay is still clicking from step 8.

NOTES:

a) There are too many if, an, nor, for’s to state every possible reason for the lights not working but usually if the wiring is OK then you need to check the Fuse or the Light Bulbs. If those are OK, re-check the wiring just to be sure, double-check all of the connections.
b) There are different type of heat shrink and most will work OK but the most important thing to remember is that you want to keep as much dirt and moisture out of the connections as possible. What is the best way; use heat shrink with adhesive inside of it and when you shrink it, the adhesive will melt and seal the joint.
c) The wire gauge that you use will depend on the total current (amperage) draw of the lights, usually based on the wattage of the lights. Using a larger gauge is better than a smaller gauge wire because of safety factors and the larger gauge wire will allow the light to run at their brightest and last the longest.
IF you have smaller gauge wire than what should be used, i.e. 16-ga instead of 12-ga, consider wiring the lights with two pieces of wire, each light would have its own power wire from the relay BUT both wires would go back to pin 87 on the Relay.
d) Always fuse the power wires especially the battery wire.
e) Always use a Relay to control the battery power.

f) Here is a quick wire gauge reference:
16-ga = 10 amps
14-ga = 15 amps
12-ga = 20 amps
10-ga = 30 amps

Keep to these wire gauge sizes and you will not have a problem with under-rated wiring and the lights will burn their brightest and I think that is why we put lights on in the first place to be bright and to let people know we can do it, I did.


I hope this isn’t too confusing; I can get carried away very easily.

Any questions e-mail me @ nnf000@gmail.com

gsb


110 watts of light can get by on a 16-ga wire but 14 or 12 in your case is far better.
The relay take the high current switch out of the cab, using a switch or the parking light circuit will reduce the chance of a fire in the cab.
 
Last edited:

My '94 also has those same connectors even though I didn't order fog lights.

As Tedybear said, it's cheaper for Ford to put the same wiring harness in every truck coming off the assembly lines and just leave the connectors for unused options in place.


As for your voltage issue, I would lean toward it being a poor connection somewhere (either your ground and/or where the two wires are joined for your two lights). Adding the relay is most certainly a good idea, though if there's another issue at the lights, it may not fix the problem you were having with only one light coming on.
 
Thanks for the input. Looks like this is definitely on the after i'm healed up from surgery list. It will be warmer then and i can buy the wire and stuff bit by bit. I did disconnect the lights. Disconnected at the battery so there is no power at all running to them. If i got another warm day might hook it back up and try hooking up just the single light that wouldn't light up to determine if it's the wiring connection method. I'm guessing it is.

Two things about this though. When it comes to wiring it into the fuse box i get the theory behind it so i don't forget to shut it off. The thing is though i really don't wanna cut into my stock wiring harness. So is it fine to run it to the battery provided it's properly fused and grounded and ran through the relay?

Also when it comes to the relay what i'm wondering is for a 4 pin relay with pin 87 being your hot when the switch is on. Would you run both wires off each light to that single pin? If so what would be the best way to join the two wires so it makes one single wire coming to pin 87? I was thinking a 5 pin relay would make more sense till i read in the link posted that 87A would always be hot. Sorry i have never really done much electrical beyond trailer wiring which is about as easy as it comes i would think. I have done some household wiring but that was also simple. My dad connected at the breaker and i made the connections at the appliance or outlet. Nothing real complicated.
 
There's no problem with running straight from the battery provided everything is fused properly (which should go without saying anyway no matter how you do it). You would just have to remember to shut it off every time (so I guess a danger would be coming back to a dead battery if you did forget).

I always solder my wires together and then insulate them with heat-shrink tubing, though I think you'd also be fine using common wirenuts (twist-on) to join the wires together (yes, you can also just connect both wires to pin #87 using a single female spade terminal). Don't try to use those crimp-splice things they sell though, they don't handle the current well (and tend to lose their connection with age).
 
Are you talking the T tap splices? Where it's two wires into one and you clamp down on it with pliers? http://www.autozone.com/autozone/ac...e-terminal/_/N-4au6?itemIdentifier=88098_0_0_

like those?

I was gonna use those on something and then after buying them and getting them home i looked at it and was like yeah these are not as good as they appear. I think i would go the age old wire nut method before those. Unless it was a pinch and i need a fix to get me home and only had those. As for the dead battery don't think that will be an issue. I have a routine when i pull in anywhere that i check all light switches. Shut my radio and CB off. Turn the heat or blowers off. So shouldn't have a problem. That and when i come home i have to kick the off road lights off, people for some reason don't like those bright bulbs at night driving through the condo complex. :icon_rofl: If i get brave wiring my CB to the battery will be on the list at some point. That's after i figure out how to remove the stock cupholder console so i can put a mount in it's place.
 
Ok. First question which is most important is this. I have two 6 inch off road lights on my front bumper running 55w h3 bulbs. So total of 110Watts. I replaced both bulbs and redone the wiring. When i put them on i didn't pay attention and the wiring harness that came with the lights had either 16 or 14 awg. I upped that to 12 awg. So running 12 awg wire in the hole set up. Other then the ground wire which is the 14 or 16.
I currently have the lights grounded to my steel license plate bracket on the bumper. The power wires currently come together with a wire coming off the switch and all three are joined with a 12 gauge wire nut. From the switch out to the battery i have a run of 12 gauge wire. It is fused with a 15 amp fuse inline. So here is the issue. My passenger side light comes on and reads the full 12 volts. The drivers side off road light however does not and reads around 6 volts. I'm lost here because if the wires are joined with the same lead wire i would think they would be getting the same voltage at each light. :icon_confused: So what do yall think i have going on? I'm guessing it has to do with high resistance on that one light maybe? The thing is this worked before i rewired and replaced the bulbs. Both lit up fine. Until one burnt out from age. It was a couple years old.


Tractor Dan,
How did your Hip Surgery go, up and running around?

Back to the lights.
Always use relay in high current switching.
The power for the lights should come directly from the battery via pin 30 and pin 87 on the relay.
The power to switch the relay can come from a switched position on the fuse panel or even off of anything that is controlled by the key to the switch, then to pin 85 or 86 on the relay.
Always use a four pin relay, the five pin relays are useful when needed but pin 87A will be hot when the switch is off.

As far as a voltage drop, something has to using up the voltage, burning it off so to speak.
Could be poorly sized wire, could be a short somewhere, could be poor connections or grounds but it is very unusual to have a different voltage from the same power line.
The light that burnt out, was it the 6 volt one, lighting can be adversely affected by low voltage as well as high.


Do not use T-Taps, PLEASE, they only lead to problems further down the trail.
Solder all joints and use a heat shrink with adhesive to seal things up only after you check to make sure everything is working correctly.
Run a ground wire, properly sized, from the lights back to the battery or to a ground stud near the battery. (seems like extra wire and work but in the future when your lights are still working you can thank me).
The ground wire should be at least the size of the power wire and grounded at the battery.

The headlights can be wired the same as the off road lighting.
Use two relays, one for each beam, and use the existing wiring (after you find your problems) to activate the relays.
There are HD Harnesses out there to rewire the headlights, so either do it yourself or buy a harness.

No matter how you do the wiring make sure to double check the grounds for all lighting.

Oh ya, read my posting and see if your is done that way, if not redo it and you will have lights where others have failed.

I can go on and on about vehicle wiring, grounds and power are easy to set up but both are needed and if you keep the power and ground sourced as close as possible your current will flow better and produce the most light they can and live the longest.



I hope you are up and getting around and you can get to this project soon, if you haven’t already got it done.
 
Last edited:
I'm doing good after the hip surgery. Got cut loose from physical therapy may 2nd. Two days shy of the 2 month mark. So not too shabby.

As for the lights i haven't got to it yet. It's on the project list. I found my truck needs tie rods here soon and my dads van needs shocks and struts. So the off road lights aren't to priority. But when it comes time i'm wiring them all up with fresh wire and a relay.
 

Sponsored Ad


Sponsored Ad

TRS Events

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Ranger Adventure Video

TRS Merchandise

Follow TRS On Instagram

TRS Sponsors


Sponsored Ad


Sponsored Ad


Amazon Deals

Sponsored Ad

Back
Top