Hello -

Thought others may find this useful:

So my brake lights quit working - a quick check of lamps & fuses led me to think of the brake light switch - After replacing it, they only would work intemittantly -
So I'm under the dash with a spotter at the back of the truck so every time I push the pedal they say on - off - on - and I hear this like sizzling sound - you quessed it - bad electrical connection.
Turns out the connector (wiring harness female side) has five mini blade type connectors - the #5 pin is always energized - 12vdc - the female side on only this one connection was loose, the other four pin connections were good.

How to fix:

Unless you buy a new harness, or connector with the female connectors, you can try this - it worked for me:
The connector has a red "keeper" that can be removed - press it in and push up out of brown connector, set aside. Then you lift the little brown tabs and push the female connector out - small flat head helps.
Once out you can use a small metal pick - I used and old drapery hook - to push the metal tabs back down.
Next slide the connector back into the plastic body of the connector, and then reconnect - don't forget to reseat the red keeper!

I have brake lights once again - btw, the brake light switch at the dealer was $27.00 with tax. I figure that's not bad, considering the truck has 134,000 miles on it.

Good luck - and love your f-150 - I'll never sell mine - last of the century, last of the 1900's