2003 Ranger....Wired a third high-mount brake light into the driver's brake light harness. Worked fine while testing, but stopped working a bit later. Bulb lights fine when parking lights are on, just no brake light. Confirmed there is no power to the green lead (brake light) when the brakes are applied (there was before - it worked normally before I started this) Passenger side still works normally......even while driver's side doesn't.

Any ideas? Can't find a fuse, but assume both sides would share a relay / fuse?

Help!

Thanks

 

Well let see, there is only one filament in a 3rd Brake Light Bulb so just how are you going to connect the Parking Lights and the Brake Lights which would include (if wired like mine) the directionals ?
Remove the mod you did and get the system working again as OEM.
Wire up the 3rd Brake Light as an independent light, not part of the rear wiring harness.
If you have a two bulb tail light you need to get the power for the light before the Multifunction switch in the steering column.
The third brake light needs “brake only” power you will need to run a new wire from the brake light switch to the 3rd Brake Light.
The brake light switch can be located on the brake pedal; don’t disconnect any wiring that is there, just add a jumper or splice in to the output wire, (normally open side of the switch).

If you have a three bulb setup then you can find the wire you are looking for under the driver’s seat, start probing the wiring or get a schematics or do the same as above from the brake light switch.

 

Thank you for the input. I realized as I was messing with it later that I can't do what I was trying to because the high-mount brake light would blink with the turn signals.

I am also chasing a water leak that is either the rear window (fixed type) or the high-mount brake light on the cab. I took down the headliner and now have access to the brake light harness. I assume I can do it from there since that one doesn't flash with the turn signals and are single filament bulbs (I think).

Thanks again!

 

Exactly !
You can do as I suggested and run a new wire.
Didn't your truck come with a 3rd brake light ?

A lot of the 3rd brake lights leak.
Either a new gasket that you will have to make or a new light that has a new gasket.

Why were you trying to connect the 3rd brake light to the driver's side tail when you had a harness already there ?

I purchased an LED 3rd brake light that has cargo lights, that I connected to my directionals; got the idea from the Ranger Site.

Luck