Fog Lamp Switch - Burning Hot!!

[LFernandez]

Good Day everyone. .



I had fog lamps installed by the dealer upon purchase of my truck. A year later, they stopped working. Took my truck back to the dealer and they stated it was a faulty relay. I tested them for a couple of minutes and all seemed well. I have recently noticed when I switch the fog lights on, the switch gets HOT, not warm, but HOT. I can also smell the escence of the hot electrical smell. I looked at the back of the switch and the wires that are plugged in to the back are melted! My knowledge of electrical systems is very limited and I am on my extended warranty. I will not take it to my local dealer as last time they lost my truck and reported it stolen. That is another story. Any ideas where to start looking? Could the relay be bad again, or should I be looking for a short? I appreciate your feedback and time.

 

[LFernandez]

Here is a picture of the back of the switch.

 

[Crunch]

My knowledge of electrical systems is very limited and I am on my extended warranty. I will not take it to my local dealer as last time they lost my truck and reported it stolen. That is another story. Any ideas where to start looking? Could the relay be bad again, or should I be looking for a short? I appreciate your feedback and time.

I'd say it's a short. My experience with shorts has been that the short is near the heat and burned areas. The switch is probably bad.



One other thing: You need to find a new dealer for service, my friend. In a hurry.

 

[rbattelle]

Remove the switch immediately, just in case.

I agree with Crunch - it's probably a bad switch. Unless the knuckleheads at the dealer used the wrong gauge wire.

Ryan

 

[JDerrick]

is the switch wired correctly into a relay, or is that switch and the light gage wire carrying the entire load of the fog lights??????????

 

[pservano]

The amperage rating of the switch is probably lower than the current draw the fog light requires. Change the switch and ensure it is the correct amp rating. The only way I can think to measure current draw is by using a clamp on DC ammeter. The gauge of the wire looks okay. I would be using at least 12 AWG wire for a fog light and an in line fuse, so just in case you have a short or overheating the fuse will open up and prevent electrical fire.

 

[LHanks]

If I'm looking at it right, it appears that the hot spots are right where the crimps are. Tech may not have crimped the connectors tight enough. Looks like your getting high amp draw between the connector and the wire. Do you have a volt meter; If so, what is voltage on the 12v feed and then on the two to each light; the top one looks OK. Before you go to the hassel of bringing it in, borrow some good crimp pliers and replace the two that are scorched, then recheck voltages. Heat from loose crimps will travel to the switch and down the wires (middle wire insulation shows heat scorching)

 

[Hoefler]

I would check the relay. If the tech at the dealership found a bad relay, he may have connected the wires to the relay wrong or just bypassed it all together and left it out. The contacts in the switch are burnt, the heat follows the terminals out from the switch. It is the contacts that is rated for the intended draw in the switch. Replace the switch, the terminals on the wires, and check that relay.

 

[LFernandez]

Thanks everyone for the help. I have a new switch and I will be changing out the burnt terminals that connect to the spade terminals. I will let you know how it turns out.

 

[Pawpaw]

If you want to, you can eliminate that fog switch and most of the wiring & relay.



My SLT did not come with fog lights either, but I learned on the TDR that most of the factory wiring is already there.



If you look in the left front wheel well, you'll find a harness with a connector on the end that isn't connected to anything. That hooks up to the harness that runs between the two fog lights. Replace the headlight switch with one that has the fog light feature. The switch cost about $30 and took less than 5 minutes to install.



I didn't even have to install a fuse or fog light relay. They were already in the fuse box.





Bob

 

[Paladin1911]

If you want to, you can eliminate that fog switch and most of the wiring & relay.



My SLT did not come with fog lights either, but I learned on the TDR that most of the factory wiring is already there.



If you look in the left front wheel well, you'll find a harness with a connector on the end that isn't connected to anything. That hooks up to the harness that runs between the two fog lights. Replace the headlight switch with one that has the fog light feature. The switch cost about $30 and took less than 5 minutes to install.



I didn't even have to install a fuse or fog light relay. They were already in the fuse box.





Bob

+1. I did the same thing. Never had any issues, it's like the truck came with them from the factory.

 

[JMarketos]

I'm an electrical engineer. I have a hunch that Hoefler has it on the bullseye. I suspect they may have connected the wires wrong when they replaced the relay, and now the switch on the dash is controlling the full current through the fog lights (which it isn't supposed to do - that's the job of the relay). The re-wiring will be a fairly easy fix once you find someone who knows what they are doing. Get it to someone who knows basic DC electrical systems and get it fixed correctly ASAP. Don't use the fog lights in the meantime- keep them turned off. This is how dashboard fires start !

 

[JDerrick]

<<<<<<<<<<< tips a glass to Jmarketos. Oo.