Originally Posted by SirGeoff
Thanks "Joes06tacoma":- Yes I am using the pre-wired factory harness - I have installed the 2 OEM compatible foglights and plugged them into the existing plugs taped above the fog lights on the bumper - too simple; I purchased a toyota equivalent Relay for the fuse box - and plugged it into the approriate fuse location; now, all that's left is to wire the 3 pronged switch into the existing factory 4 contact switch from behind the dash switch blank.
That's where the dummy in me takes over.
First of all I didn't realize that there was a dash indicator light, so I guess that would be the 4th contact (which, as you mention, my rocker switch probably won't activate. - the only "FOG LIGHTS ON" indicator being the light on the toggle switch itself?)
I do have a multimeter, but this is where I get lost.
I realize I need to have the low beams on to activate the fog lights, but how to use the meter to determine which contact does which has me baffled? If anyone could dumb-it-down and walk me through the steps a little more that would be really appreciated.
Thanks for any help...
I found the wiring diagram and looks like the fog light relay is negative switched. That makes what I said already wrong.
Second link shows the dash illumination, including the factory fog switch internal light bulb.
Looks like solid green wire is dash illumination (+). So you would actually connect that to the ground on your new switch to make it light up when you switch the negative side of the circuit on to the fog relay. Green with white stripe is negative dash illumination, you don't need that.
According to the wiring diagram in the first link, you should have a blue wire coming from the negative terminal of the fog relay's coil. That would go to your outgoing power terminal on your switch. (center terminal usually)
There should also be a white wire with a black stripe. That's chassis ground and should go to the terminal on your switch marked incoming power. (sounds wierd, but you are switching the negative side of the circuit.)
Are you sure you have the right plug? Looks like you have two hanging out of the dash in your pic.
As far as the meter. If you are trying to find a positive wire, then attach the black wire on the meter to a ground and probe with the red wire to find positive power. If you need to find a negative wire, attach the red wire to a source of power and probe for ground with the black lead. Meter should be set to DC volts. We are looking for 12volts, so set the meter range (if it has one) to 12 volts or higher.