Daughters 03 mountaineer. Have changed the brake light switch, bulbs and checked the only fuse I could find for the brake lights. She can drive it by doing the override under the column but still has no brake lights and is an accident waiting to happen.

any ideas what else to check? Is there a relay or another fuse I could be missing? I'm lost. Any help appreciated.

 

Check the owner's manual for relays and fuses that you might have missed. If you don't have the manual, it can be found here: My Vehicle Owners Guides & Manuals

If the brake pedal position switch were bad, I would expect OD and cruise to be inhibited based on my older (pre-2k) Fords.

If you find a blown fuse, it could be a sign of a more serious problem like a short.

Beyond that, I don't know what else to recommend without a wiring diagram. You could have a bad ground, but you'd need a manual / wiring diagram to know where the ground(s) is located. A wiring diagram would go a long way towards showing you what's common between the two tail lights.

 

Do you have a multimeter or test light to confirm if you have power to the brake pedal switch? The symptoms you describe are completely consistent with a bad switch. Are you sure you reinstalled the switch correctly and that it is being correctly actuated by the brake pedal? Did you get the updated style that requires you to change out the connector? If so, are you sure you made good connections when installing the new connector?

As for the OD and cruise not working if the switch were bad - that might be the case if the switch were shorted or depressed all the time. But in the case of an open switch, the OD and cruise has no idea there is an issue and therefore both would still work just fine. There is a brake pressure switch on the master cylinder that serves as an emergency disable for the cruise in the event the stoplight switch fails.

-Rod

 

Actually no, I am not certain that it is installed correctly. Was doing it in the rain,by flashlight. It seemed to take forever to get it back on and locked in. Doing it mostly by feel. Yes it was a new style with wiring and a connector. I am not sure that I got it wired right. The wires of the new switch are red/green. The wires that those connect to are green with red stripe/brown with black stripe. I connected green to green with red stripe and red to brown with black stripe. I won't be able to see the truck again til next week. I will take a test light with me this time. It was a quickie deal. She called, I googled, ran to the parts store for a switch, assuming it was a plug and play replacement like 99% are. Didn't realize it was going to be such a hassle.

Thanks for the replies.

EDIT Looking at the owners manual at the link provided, I don't even see a fuse for brake lights/brake lamps/stop lamps...anything. I have looked at it several times thinking I just missed it. Had my wife and son look as well, no one sees anything for brake lamps.. Am I missing something?

 

Fuse F2.23 (15A) in the Central Junction Box is the fuse that feeds the stoplamp switch and the brake lights.

The stoplamp switch is just a switch, it is not polarity sensitive, so there's no real need to know which wire goes where, as long as the connections are reliable.

I remember there being something slightly less than intuitive about the way the switch attaches to the brake pedal, but I don't recall the specifics currently.

The stoplamp switch powers the Center High Mount Stoplamp (CHMSL) directly and goes through the Multi-Function Switch for the "normal" brake lights, so you might want to check to see if the CHMSL comes on when the brake pedal is pressed. If so, then your switch install was probably just fine.

-Rod

 

Found the fuse. It was blown. Replaced it, immediately blew that one. Checked my wiring, installed another, it blew. Apparently there are more serious issues than the switch. A direct short somewhere along the line. Oh boy... Tracing these things is never fun.

Only clue I have is, she said one of her turn signals was blinking fast, checked it and it was not working (lighting). Was going to buy a bulb but the next day while driving, she tried it and the turn indicator worked all the sudden. Parked at work, went to leave after work and was stuck in park, had no brake lights. Been that way since. Not sure what the turn indicator has to do with it, just odd it all happened pretty much the same time.

I called and talked to her about it and she said her high mount brake light has been out for a while, just never got a bulb for it.

 

That's a bummer. If you'd like the wiring diagram for the truck, send me a Private Message with the request. Please include the year and model and include what it is you're looking for (stoplight switch diagrams) along with an e-mail address for you that can accept PDF attachments.

-Rod

 

you might check the rotating plate that moves the gear indicator and has the brake depress before shifting into gear actuator, there are 3 allen headed screws that if they become loose enough, the steering column does not know you are pushing the brake, pulling back on the shifter, and therefore will not let you out of park. its not very easy or comfortable, especially for a large person, a mirror might be used to locate them, but the only way I found to actually handle them is to move the seat all the way back, remove any access panel that will grant you access to the steering column lay upside down in the floorboard with your feet and legs either out the door, or up the seat. While laying there you can see these bolts, and touch them, but have fun trying to tighten them. Hope this helps.

 

In the case of the original poster the brake lights were not working so that points to something in the circuit prior to the lockout. But this plate and screws you mention are certainly a good thing to keep in mind for other Explorer and Mountaineer owners that are only have trouble with the shift interlock. Thanks for the information!

-Rod