Looked around but couldnt find anyone who had done this. I'm replacing my lower valence and putting PIAA 520's into the new one and would like them to act just like my stock ones now, turning on when I pull out on the headlight selector switch. Is there a way I can do this? I'm not the most electrically inclined so use small words if you reply with how to do it

TIA, ZelenVR

 

I've wondered about this too, and everybody said that it couldn't be done easily...

 

It is not hard at all.

1. Did you have the factory ones installed already ?
1.1. The relay for PIAA lamp set has an input from the switch ( in the little black connector for the switch ). Just wire this to one of the connectors for the stock fog lamps, and tape the other one closed.

2. If you did not have the stock fog lamps installed, but you do have the switch installed :

2.1. With the diagram above, the yellow wire from the stock headlamp ( w/ fog lamp ) switch will provide power to the PIAA ( or other ) relay, once you install fuse #27 in the CJB.

Both ways will work, depends on how much you have installed already.

 

SSCULLY, so all I have to do is plug in the #27 fuse, and hook up the lamps to the yellow wire? This wire goes into the switch correct?? Sorry, I'm not very good with these diagrams.

 

@ SSCULLY:

I have factory fogs on mine so which wires do I splice together for the switch to run the PIAA's? Do I just cut off the old connectors?

Thanks, ZelenVR

 

Close.
With '00 and newer MY trucks, the output of the fog lamp switch ( yellow wire ) would be connected to the power side of the coil on the relay for the fog lamps.

The power for the fog lamps would be from the battery, through the relay.

One thing, did you get the fog lamp switch installed ? You might have to add the yellow wire, depending on the trim level of your truck.

 

My truck is an XLT, the switch pulls out for fogs, but it isn't wired for them....

 

I have the stock valance lamps and aux fogs on the headlite switch.
A second rocker switch installed in the fuse cover selects between the two.
All that is needed is one relay and one lead thru the firewall to the rocker switch.
I also have custom side markers/turn signal lamps that only work when the park/headlites are on.
There are very few american makes that have good side/turn signals to be seen by a vehichle coming along side at nite for turning or lane changing.

 

Take a look at the switch for the PIAA lamps. The small black connector should have 3 wires. In is for power in, one is power to the coil on the relay, and the other is ground. I want to say the PIAA switch power is a white or a white with a red stripe ?? ( been awhile since I have seen one, and it could have changed )
The power to the relay, you want to splice to the factory fog lamp wire that is Tan with an Orange stripe. This is at the connector for the factory fog lamps.
I would not cut them off myself, incase you want to go back to stock, but if you do, leave room so you can solder them back on to the factory harness.
I would just cut some of the insulation off, and install a solder T splice with the Tan / Orange wire, and tape the connector up with a splice pad and tape. That is just me, if you don't plan on going back to factory ever, cut away.
Either way, don't forget to take care of the other fog lamp connector.

 

Just noticed your MY also. '99 is slightly different then the '00 and newer. Did you install a '99 headlamp switch, or a '00 and newer ?

This is the diagram for your MY truck, if it is a '99 switch :


In your case, the ground side of the relay is what is switched, not the power side like the '00 and newer MYs.

If you place a meter over the pins 3&4 on the headlamp switch, and pull the fog lamps out, the circuit should be completed, if it is a '99 MY switch.

You will need to check which MY switch is installed, and adjust your install accordingly.

Almost a given you are going to need to add the wires to the headlamp switch connector, as in '99 most wiring harness were not universal like they were in newer MY trucks.

 

As long as your 520s are less than 55 watts, just lop off the OEM light from the connector and splice them in in place of the OEM lights.

I did it to my PIAA airdam. Everything is fine. The PIAA 520 SMRs I have are 55-watt bulbs. The OEM lights are 55 watt bulbs. If you're replacing them with like wattage, there is no reason to splice in the PIAA harness.

-Joe

 

Unfortunately these are 85w lights so I guess that wont work. I guess I can just wire them like any other added lights, but splice the PIAA power wire into the tan/orange wire right? Will the additional wattage have any effect on the stock wiring??

 

Still curious about this. If I wire the lights like any other added lights (main power from the same place my other added lights are and ground them to the frame) can I still have the factory switch control the on/off function using the stock wires?


Thanks, ZelenVR

 

To use the factory switch, you'll simply wire up the lights as though you're using an aftermarket switch and relay, but instead of using an aftermarket switch to trigger the relay, you'll use the OEM fog light wiring to trigger the relay, that's all.

-Joe

 

OK, cool. I think I can do that. So I'm guessing that I need to splice the White/Red wire going off to the right into the factory wires. There is an orange wire and a darker (black?) wire going into each of the factory connectors. Do I just splice the w/r wire into ONE of the orange connector wires and just leave the other stock connector alone? I'm working on it right now out in the garage and am about 30-45min from being ready to start the wiring.

-Also, the wires going up to the supplied switch are on a connector so its not already connected like in the picture.