Ok so I recently caught the bug for the back up lights that everyone had post pictures of. I have everything hooked up correctly, and the worked well while checking them. Well, now that they are all hooked up and ready, I have blown 10 fuses trying to figure out the problem. From the battery to the switch with LED indicator works, from the main supply line from switch to the lights in the back work fine, plug the main hot wire into one light and it works fine, hook main hot wire into other side and it works fine, BUT when you hook up BOTH lights it blows my fuse! I have checked everything it seems like and can't find any crossed or exposed wires. The wire are wrapped in electrical tape also so there nothing exposed. I am clueless guys, I need your help! Also, my lights are apparently fogs that are made by pilot and they are blue/yellow lights. This doesnt produce a white/bright light and wanted to know if theres a way to change the bulb color and lense color? THanks alot!!!

Also, only thing that I am second guessing is the fact that I used 16 gauge wire in some places since the harness was too short.

 

Something is not correct with the install, or the harness change.

1st check the switch install, to make sure ground is on the correct terminal. This would be the case if you turn the switch on, and the fuse blows straight away, the switch is connecting ground to the lead to the battery.

Use a fused 12V supply, and apply power to the lights individually at the Y adapter, towards the lights.
- This will test each light individually, to see if there is an issue with each light.

With the Y adapter unplugged, test for continuity at the Y adapter to ground.

Did you ground the lamps as shown in the instructions ?

When you lengthened the harness, did you solder and heat shrink tube the splices ?

When routing the wire, did you pull it down the length of the harness, maybe damaging the insulation ?

Does the fuse blow the moment you turn the lights on, or after time ?

 

Thanks for the response. I will try another 12V supply soon. Yes, the lamps are grounded and I also used weather proof butt end connectors and heat shrink. I checked all the wiring and cannot find any exposed wire. The fuse blows the moment the switch is turned on with both lights connected. The fuse will not blow if only one light is hooked up to the wire.

 

Sounds like the lights are simply pulling too much current for the fused circuit, so the fuse blows.

You need to first determine what the current draw of each light is, then design the rest of the circuit around the pair's draw.

It would also help if you identified which fuse is blowing (whether it's one in the truck or the one identified in the drawing) and what it's amperage value is.

 

The fuse that is blowing is the one like above on the fogs wiring harness. The only thing that these lights use from the truck are the ground and 12V power. Thanks alot guys. Anyone have any tips for testing the light or how to?

 

If you can hook up either lamp and it works but, when blows the fuse when BOTH are connected, it is very clear that the lights are pulling too much current for the installed fuse.

It is as simple as that.

Remember that fuses should be specified to protect the wiring in use.... Generally, the fuse should be selected to protect a wire size that is two gauge sizes smaller than what is in use.

 

Did you ground the lamps as shown in the instructions ?
They have to be grounded to do anything at all, the question was centered around using the ring terminal at the base.

When you use a single lamp, are you testing with the same working lamp ?
- Unplug the Driver's side lamp 1st, turn on see if the fuse blows with the passenger side lamp only
- Unplug the passenger's side lamp 2nd, turn on see if the fuse blows with the driver's side lamp only.

Are the lamps 55 W each ?

 

Guys I really do appreciate the help! Yes, these lights are the simple $17 special at autozone pilot name brand fog lights. The wiring picture above is not from my lights, BUT the drawings are identical except for the fog light image. So, let me clarify again, the wiring diagram is the same as mine. I do have the lights grounded to my bed near the spare tire, so the ground is a perfect. I will try to explain it very clear to let you all get a better understanding. The lights are 55watt each, the plain simple driving/fog lights.
If the lights are drawing to much power, what should I do? I know putting a larger fuse is almost a danger waiting to happen.

(I used a checklight/meter to make sure power was supplied)
1. From the battery, through the fuse, to the switch, is good.working.

2. The switch is grounded and has LED indicator.

3. When switch is in on position, LED lights up correctly, and switch works fine.

4. From the main supply wire connected to the switch, is hot when switch is turned on. I checked with meter and it has power.

5. When HOT supply wire is plugged into driverside light. (only driverside) the light works fine, no blown fuse.

6. When HOT supply wire is plugged into passenger light. (only passenger) the light works fine, no blown fuse.

7. THE PROBLEM. When the HOT supply wire is plugged into BOTH lights, (providing power to both lights hooked up)the fuse blows immediantly. I just don't understand why the lights work seperate and I have tested them both on another battery, but when they are both connected to run together, the fuse blows immediantly.

Hope I explained the situation a little better. I hope I get this all worked out! Thank you for helping me, just hope someone has the right answer!!

 

What size fuse is installed ?

55 W lamps draw 4.6 A each, for a total of 9.2 A operating amps.
This does not take into account a poor splice that is acting as a high resistance load. i.e. if the butt connectors was crimped with an auto style crimp pliers ( the arc on both sides ) or one of the crimps pulled apart.

The fuse should be sized for 80% of the normal load = 11.5 A, which the closest is 15 A.

16 AWG wire should be fine for any length run on a truck, for a 9.2 A load. Are you sure it is 16 AWG you added to the harness, not 18 AWG ?

The ground is on the bed, or on the frame ?
You really should use the frame or the ground for the trailer tow adapter, not the bed. This could be a poor ground.

 

A high resistance connection DECREASES current. Same for a "poor ground" provided there is not a short-to-ground in the power circuit. Neither will cause a properly sized fuse blow.

This is the key question. Perhaps someone misread the markings and used 1.5 A fuses or otherwise provided the wrong amperage fuse.

 

After talking to my grandpa, with me added my extension wire that is 16 gauge, thats whats causing the problem. I figured the included wireharness in the kit is 18 gauge. Sound right?

 

No. See my above posts ...and go LOOK at the fuses.

 

I checked the fuse again to just be safe and it is a 15 amp fuse. I went through about 10 of them just trying to track down the problem that I have yet to do. Would just re-wiring the entire light system with 16 gauage wire work? What I do not understand the reason for that is the lights worked at one point before they were mounted? Im about to just buy a whole other light system. I have no idea.