Bosch Relay Gurus

I am trying to figure out how to add stock foglights to my 01 Explorer Sport. I have gone through and read multiple threads, and looked at many stock and aftermarket wiring diagrams. I think I have most of it figured out except 1 wire. My plan is to use the original 95-01 stock fog light switch with a Bosch relay to activate the lights. I know I can wire the relay to turn the foglights on at anytime using an ignition power source, but I want to stick with stock. I would like to wire the foglights to come on only with the lowbeams and go off with the highbeams to keep it legal. Which wire would I tap in to to make this happen. Also would there need to be a fuse inline with this wire?

I found this diagram and customized it a bit, to what I hope to do. Pin 85 is the only one I have left to figure out. Any help will be greatly appreciated. I am not sure as to what gauge wire to run also, any ideas. Thanks for reading this thread.

(dead link)

 

[ghosttrain2]

Using Bosch terminal numbers,the relay's coil are 85 and 86. Treminal 30 goes to the power source ( battery) ,87 and 87a are the contacts-87 is the normally open contact, and 87a is normally closed. So, for foglights,using the factory switch:
terminal 86-wire from foglight switch.
terminal 85-ground
terminal 30-to a fused battery lead
terminal 87-to foglights
terminal 87a-not used

 

[just1me]

I am trying to wire them like this: but using only 1 factory switch as I am installing factory fogs as I have none.



and I want to wire them like this: but to work with the lowbeams.

(dead links)

 

[just1me]

This is how I got it figured out, all except which wire on the light circuit to go to for lowbeams from pin 85, would I go to the highbeam side or lowbeam side to activate with lowbeams only.

(dead link)

 

[ghosttrain2]

What do you need the brown wire from the foglights to the switch for?
Here is a simple explanation of how the bosch relays work,with a sample circuit- http://www.bcae1.com/relays.htm .
You should be able to splice a wire coming from the lowbeam wire on the dimmer switch with a inline fuse to your foglight switch, from there to the relay terminal 85, and a ground to terminal 86. Terminal 30 of relay to battery a battery positive connection, terminal 87 to foglights fused as you have it. I think you could modify the sample diagram on the link to fit the components you have.

 

[just1me]

Thankyou, the tan/org wire that looks brown is the wire to the factory switch for the lamp indicator on. A guy I talked to recommended me to do it like this , as to protect the headlamp circuit and the relay and wires from shorting out.

(dead link)

 

[ghosttrain2]

OK-Good deal, I understand now.