ok this has been mentioned before, but i had a hard time finding the original post. either way, the question didn't really get answered. my passenger fog light has been out for a year now. i have replaced the bulbs and it still hasn't worked. i figured there is a short somewhere. i even replaced the fog light fuse. what is the best way to tackle this? i look underneath the bumper and i see the two individual fog lights and their wires running towards the middle of the bumper and connecting. i follow it to another connector towards the middle and from there i'm lost. i don't know what i'm looking for or how to even test. i've just been wiggling the wires with the lights on hoping something will catch. i've tried to look at wiring diagrams but thats arabic to me. i can't follow it because i've never been taught wiring. however, understanding a wiring diagram won't show me a short...any help yall? thanks in advance

 

Personally i would take the whole light out and everything then test it at the battery, pretty much just use two pieces of wire, one positive and one negative and hook them on the terminals then to the positive and negative ends on the fog light and see if it lights up, if it doesnt then either the bulb is toast or your wiring or socket is fried.

All else fails run new wiring for the foglights and either wire them to a toggle under your dash some where or wire them into your headlights that way they'll come on when the headlights do.

Have you tried swapping the wires from the left to the right to see if it's just the harness on the passengerside ?

If it is then you could just cut the wires for the passengerside and splice them into the drivers side and put a inline fuse so it doesnt over load the wiring for the drivers side also.

 

the way the fog lights are wired - they share the same fuse and relay...

So it would appear to be a wiring harness issue - be it a bulb, bulb socket, or a bad splice...

Check for 12v at the sockets between the two leads and then back at the bumper connector where the fog light harness plugs into the main truck harness..

your losing the voltage somewhere and there is a splice in the fog light harness where the two single fog light harnesses come together

 

hey i appreciate the feedback yall. hopefully if the bottom doesn't fall out, i can head out and check

 

i'm trying to better understand wiring in trucks and i read that a relay is an electric switch that provides power or a ground to a source. they rarely need to be replaced the article stated and if i have one fog light that works, then the relay works. so its safe to assume that the splice maybe is not strong. i was gonnna try yaks idea of switching wires to see if it is a faulty passenger wire.

hey kyhi, how do i check for voltage at the leads? not sure what the tool is called?

 

You can use a volt meter (DVM, Digital volt meter, having one is very handy) or, a simple test light. You can get test lights for anywhere from 90 cents, to 30 bucks, depending on how fancy you want. With a basic test light, just ground it somewhere, (bumper should work) and then probe both light socket terminals with the pointy end. Light comes on, you have power, no light, no power.

 

thanks man, i'll run by autozone in a few.

 

so i bought the light test for $2. never used one before, but it stated to puncture the wires of what i wanted to test. i did that, sucked bc the damn wire was thinner than the tester. anyway, i'm thinking about buying a DVM for about $15. how the hell do you read these? there are many options when you turn the center dial.

yesterday, i was messing around with the fog lights trying to disconnect the harness and clean it with CRC electric cleaner. here are the pics i took. maybe yall can help me out some more.

this is the harness that connects to the "main" line and then runs to the spilt at the front of the bumper..how do i unhook this harness? tried squeezing the sides, nothing..tried prying middle piece, nothing..


this is following the wire from that harness to the front of the bumper..is this a splice for the two fog lights?


this is a random wire that i think splices into the lights for the fog lights. not sure what it is..


that wire runs over the front axle and plugs into this..never knew this object was here. i unplugged this end and cleaned it, still nothing..


this is a tag that was on this random wire. any idea what this wire is for or what this tag means? ..


here it is looking like sh*t with the light out...i just wanna rip the wiring out but i don't know jacksh*t about that stuff. also i noticed, there is an inch of water in my dirver headlight...i thought abot drilling a hole in it but im sure it would get worse.

 

Since one of them works, and the other does not, 99% of the system is working as it should, your problem appears to be in the part of the harness right by the fogs.

First, see if you are getting power at the non-working lamp. Take out the bulb holder, remove the bulb, and use a couple paper clips in the connectors, so you have something to put your test light on. (or, use the VOM, with the dial set to 20 volts DC, that would be easiest.....) DO NOT LET THE PAPERCLIPS TOUCH EACH OTHER. See if you have power across the bulb socket.

If you do, the bulb is bad. (I am sure you have tried changing the bulb though... so, don't expect this to show you have power there....) If you don't.... follow the wires back to where they splice together from the main feed, and break off to go to the separate lights, I am going to bet that is where you problem is. Have to peel back the funny tubing around the wires to get at what you want.

 

That depends on which meter you have. When working on your truck you will only use 2 selections V= (Dc Voltage the V~ is for AC voltage..that's for your house, course I'm assuming your meter has 2 selections on the ****) The other selection is an upside down horse shoe or I think it's an Omega symbol. This is for Ohms or Continuity. Use this for checking for grounds, shorts and opens. Will only confirm a condition won't tell you where it is.

With your fog lights on you should read 12V from one pin and 0V from the other when you have the black lead connected to ground, and 12V between the two pins in the plug. Checking the continuity of the neutral side is pretty ease, pull the plug and check for zero ohms between one wire and the chassis. That will tell you one side of your circuit is good. you'll have to disconnect the battery and short the other side of the circuit to ground (or neutral) to check the other side.

This site will give you the correct symbols on your meter cause the keyboard won't do DC correctly.