Well I kept myself busy today and one of the things I did was cut and mod in another fog light switch to run some offroad lights off of. I managed to get the wire harness to go with it and was curious if anyone could tell me what the wires were previously wired as. There and 4 wires, LB/BK, Black, RD/BK, and TN/OR. I already have the relay I will need for this setup. Thanks for the help.
-Luke

 

This switch works by grounding.

LB/BK: relay to switch
Black: To Chassis ground
RD/BK: Instrument lights for switch icon
TN/OR: Fog Lamp "ON" LED

 

So Bob how would you suggest I wire this then. I know you have already done something similar which is where I got the idea so thank you for that. I see I need to ground the black wire and illuminate the switch through the RD/BK wire at the insurment panel. As for the other two wires I am a lil confussed. Thanks for the help tho!!

 

Here is a possible way to wire auxiliary lighting to operate through a factory Ranger foglamp switch using a common automotive relay. It is critical that the two 12v sources are adequately fused and that large enough wire is used, especially for the constant 12v source to the relay and the wire from the relay to the lights. This depends on the total wattage of the load which can be converted to amps. (amps = watts/12v). Also the relay must be of adequate amp rating to handle the load.

The diagram has a flaw, though. The wire to pin 6 is coming off of the heavy wire to the lights. It should have a fuse in it that's correct for the smaller wire to the switch and then to ground.

Where it says "Keyed 12V", it would be possible to substitute other triggers like the high beam wire or the headlight/parking light 'on' wire.

Pin 3 LB/BK
Pin 4 BK
Pin 5 RD/BK
Pin 6 TN/OR

 

Thanks Bob. I am gonna print this out so it is easy to find. Just a thought, would it be cool to hook the RD/BK illumination wire to the RD/BK wire on the original foglight switch or will that be too much of a draw.

 

That's how I did mine. The bulb doesn't draw much at all and Ford tends to use a minimum 20~22 gauge harness wire regardless of how low the design current is. That minimum size is surely for mechanical durability rather than current load.

 

Then I now know what to do. Thanks again Bob!!

 

Sorry to resurrect an old post like this but it was easier than starting a new one. I need to know what size fuse to put in this wire. The power wire to the aux lights will be 14 ga wire and the wire to the switch will be a 16 ga wire. I know that without fusing the wire here I can burn my switch up and that would be bad. Now what size fuse should I use? I appreciate any help. Thanks
-Luke

EDIT: I forgot to mention the lights are 55w halogens

 

That just powers an LED that draws 20 or 30 mA.

I would use a 5A inline fuse to pin 6 and position it on the powered end of the wire - in other words, where it begins at pin 87.

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Assuming 2 lights @ 55W each, the lights will draw (2 x 55) / 12 = 9.17A @ 12 volts

I would use a 15A fuse in the 14ga wire going to pin 30 of the relay. The fuse should be positioned as close as possible to the powered end of that 14 ga wire.