No brake lights even after changing brake switch - bulbs are good

[SyberTiger]

So I thought I had the typical worn out brake pedal stop light switch like so many of you have had. I changed the switch out with a new one installing it exactly the way the old one was (wiring harness connector plug pointing to the rear of the vehicle). Unfortunately, this did NOT fix my brake light problem.

In a nutshell, some old dude followed me to tell me my brake lights weren't working. I turned on the hazard lights, running lights, and turn signals to verify the bulbs were NOT burned out. All the light indicators (except for the brakes) worked so I assumed it was the brake light switch. And yes, the third brake light (Center High Mount Stop Lamp) does not come on either. Before installing the new switch I checked the fuses just for good measure.

Anyone have any idea what the issue is? The one thing I can you is when I gently tap the brake pedal (using my hand) I can hear what sounds like a relay sound. Checking a little closer it's a relay called the "Police IVD" relay that located in the power distribution box under the hood.

Dang, I hate it when I'm the only one ever to have this problem.

I looked up what IVD is because I didn't know: "The terms Advance Trac and Integrated Vehicle Dynamics (IVD) are different names Ford has given to the same system. Two interchangeable names, one system. IVD is a function of the ABS module. It uses ABS and traction control functions together to help steer the body of the vehicle to match the driver’s demand."

 

[SyberTiger]

It's really frustrating to look at the owner's guide that came with the Ex and see this:

 

[FirefighterJose]

I had a similar issue and found it to be a fuse... After I swapped the brake switch!
It wasn't in that location though, it was the row above it. #25 or something, it was a yellow 30amp fuse specifically for the rear brake lights, not the pressure switch.

 

[SyberTiger]

Solved!!!

Mystery solved! It was the IVD relay after all. Dang, I switched this relay with another one yesterday and it didn't solve my problem and because I heard the relay switching everytime the brake was depressed I had assumed it was working....WRONG.

I'm not sure what the deal was yesterday but today I borrowed yet another relay and tried it out and lo and behold the brake lights are all working. Lesson learned: Even though you hear the relay energizing it does NOT mean it is fully switching on.

Likely a contact in the old relay is worn or it's just not energizing all the way. In fact, when I tried a different relay today you can hear it "click" a lot louder than the worn out one.

p.s. Part of my problem diagnosing this is because for 2002 Ford Explorers they have "early" and "late" builds with and without the IVD feature which means you have to look for the search schematics to figure out how your particular models works.