2nd Gen Non-Engine/Transmission Fog lights always on.

[DarrellB]

I just got my PIAA fog lights today and went to install them and noticed right away when I went to splice into the stock Fog Light wiring harness that there was power going to the harness without the switch being turned on. I didn't have a lot of time to mess with it before I came to work but what I do know is that my fog lights have power to them all the time, with or with out the switch on. They even have power with the key turned off. The only way to cut power is buy removing the 15amp fuse under the hood.



Does anybody know why this would happen?



DB

 

[bmoeller]

Are you replacing the OEM lights, or new install?



Maybe a relay is stuck on?

 

[DarrellB]

Replacing OEM lights with PIAA's. I was going to use the stock set up as far as wiring and the switch went. The OEM's worked just fine when I took the stock bumper off but now they are getting power constantly. I can even take the relay out and they still get power.



DB

 

[Thomas]

Sounds like you have 'switched ground' on your 1999 Ram.



The circuit is as follows:



B+>15 amp fuse>fog light filament>normally closed relay>fog light contacts in head light switch>ground

 

[DarrellB]

Originally posted by Thomas

Sounds like you have 'switched ground' on your 1999 Ram.



The circuit is as follows:



B+>15 amp fuse>fog light filament>normally closed relay>fog light contacts in head light switch>ground

How would this have happened with just changing bumpers and unplugging the factory fog lights?



DB

 

[Thomas]

I wasn't suggesting that you changed anything when you changed the bumper.



I have a model year 2000 Ram that has the foglamp circuit exactly as I described. On model year 2000 Rams there is always +12 volts at one of the two wires (red w/orange tracer) at the fog light socket. The other wire (light blue) at the socket is connected to ground through the foglamp contacts in the head light switch (switched ground).



Your description of what you found on your 1999 Ram leads me to think that your wiring is the same as model year 2000. Have you actually hooked both wires that went to the OEM socket to your new PIAA's? How are the PIAA's hooked to ground?

 

[DarrellB]

Oh, I'm sorry I didn't quite understand what you where saying.



The PIAA's have a ground wire and a hot wire but also have metal housings. You are exactlly right on the wiring though, I have a red wire with orange tracer, and a light blue wire.



Yes I did hook both wires up to the new PIAA's and that's when I noticed the lights staying on. I hooked the Red wire with the orange tracer to the hot wire on the PIAA's and the Light Blue wire to the ground on the lights.





DB

 

[Thomas]

The fact that the fogs remain on with the switch "off" and the relay pulled indicates to me that you have the switched ground that I've mentioned and that the thing keeping the lights on all the time is that something is providing a path to ground other than the normal path through the normally-closed relay and switch on the dash. Have you hooked anything to ground?



I don't think your PIAA's are grounded through the metal housing - my PIAA 60 XT's are not.

 

[DarrellB]

Looked at the lights more today and they are not grounded through the housings. I didn't think they where but wanted to be sure.



I'm going to try to work on them more tomorrow when I'm off work. Should I just use the Red wire with the Orange tracer for the hot wire? Then ground the lights onto the frame or batteries.



I probable should just forget it and put my own switch and relay in, that would solve all my problems.



DB

 

[Thomas]

I think you should attach one (either) of the wires from the PIAA's to OEM red w/orange tracer & attach the other wire from the PIAA's to OEM light blue.

 

[DarrellB]

I tried that, and they still stayed on all the time. I put the white wire (hot wire) from the PIAA's to the Red/Orange wire and then took the Black wire (gound wire) from the PIAA's to the Blue wire.



Sorry about bugging you with this.



I've got all day tomorrow to mess with it so I should get it figured out by then I hope.



DB

 

[CORed]

I had a similar problem last week when installing my Catz lights, however, my problem was definitely the fact that the lights were grounded via the housing. I had to create a make-shift insulator at the mounting points in order to continue to use the OEM switch / relay / wiring setup.



When I installed Hella's prior to that which were NOT grounded via the housing (plastic), everything worked as expected.



If you definitely do NOT have a housing ground, then it sounds like something is not right.



Sorry... just realized this post probably didn't add much.

 

[DarrellB]

Originally posted by CORed

I had a similar problem last week when installing my Catz lights, however, my problem was definitely the fact that the lights were grounded via the housing. I had to create a make-shift insulator at the mounting points in order to continue to use the OEM switch / relay / wiring setup.



When I installed Hella's prior to that which were NOT grounded via the housing (plastic), everything worked as expected.



If you definitely do NOT have a housing ground, then it sounds like something is not right.



Sorry... just realized this post probably didn't add much.

Actually that's a good idea that I haven't thought of. I might try hooking them up while they are sitting on the floor it see if that makes differance.



At this point I'll try anything to get my lights working with the factory switch.



DB

 

[JBevans]

Hey DB,



did you ever figure out how to get your lights to shut off? I just tried the same thing to day, replacing the OEM with a new set. Like you I hooked up the white wire to the red power, and the black to the light blue, and like you, the lights always stay on... I ran out of time to play with them and hope that I would find somthing here at TDR. any info would help



JC

 

[DieselDoghouse]

Another alternative - inserting a relay between the lights and the oem circuit - let the d*mn switched ground control the coil of the relay and provide +12V to the relay contact set and carry +12 to the continuously-grounded lights. That way the 'switching circuit' and the 'load circuit' are separate except for the relay and you won't have to worry about the light housing becoming accidentally grounded. Never did understand this switching ground garbage that came over from Europe. If it was 120V instead of 12V would YOU switch ground (neutral)??—wouldn't meet code methinks!!