I just bought a 2000 Expedition and am making needed repairs. The first is the parking brake switch and the dash light, which doesn't illuminate.

Current analysis: Turning the ignition switch on, all dash light come on including the brake light on the dash. After a few seconds the light goes out. I'm assuming this is normal. Upon pressing the parking brake pedal to set the brake, the brake dash light does not illuminate. I've located the switch and the plunger does freely move. I've tried moving the switch with my finger but it appears solid in the mount. Also moving the switch plunger up and down did nothing to illuminate the light. I also understand that there is one wire going to the switch (green) carrying 12VDC with the switch going to ground when the switch is depressed.

My question is how do I remove the switch from the car for testing and or replacement. I suspect that I need to remove the parking brake assembly but the area is so tight that I can not tell for sure.
I'm seeking wisdom for the collective knowledge of the group for any guidance.

Thanks

 

Rather than go through all the work of removing the parking brake assembly, I would first run a jumper wire from ground to the wire going to the switch and see if the light comes on. This would tell you if the issue is with the switch or the wiring.

 

X2 - ground out the wire going to the switch to test the light,.
It does seem your switch is bad as it was just like ours.
Ford may have changed things, but the parking brake switch in our 2003 is held by a single screw.
Is there any rust on the pedal assembly?
I had a small water leak that dripped on the switch causing it to corrode.

 

That is a capital idea alloro and R&T Babich. I was thinking the same thing earlier this morning. Research (youtube) showed that the 7mm bolt holding the switch assembly in place provides the ground and the green wire provides the positive (according to the schematic).
Tonight I will locate a suitable ground, one of the brake pedal mounting bolts which secures the pedal assem to the firewall and the master cylinder. I'll secure one end of a test lead to the brake pedal bolt and touch it to the 7mm bolt which provides the frame ground point. This should tell me if it's corrosion between the 7mm securing bolt to the frame which I'm bypassing or the switch is bad.
Thanks and I'll keep you posted.

Greg

 

It is a ground issue. Connected ground test lead to brake bulkhead bolt. Tested for valid ground which proved positive. Next, connected ground lead to a probe and pressed against 7mm bolt for the parking brake switch. Dash brake light came one.

Since this test was valid, what do you guys suggest next ?

Greg

 

It's a bit tough to follow the results the way you wrote them, but it would seem your test indicates a bad switch.

 

Sorry for the confusion. Let me try this another way. Yes, I suspect the switch is the problem. The switch is held in place by one screw. If you touch the switch with a finger it seem to light the dash light. This indicates that it connects to ground at that point.

It was suggested to use electrical contact cleaner and let dry overnight. Hose the switch and plunger with cleaner. I suspect that over 16 years, it has gathered a little corrosion or dirt on the contacts.

Is this a valid approach prior to replacing the switch ?

 

You could replace the switch, but I suspect the switch is a simple enough construction where you can actually get into it and just clean up the contact surfaces and make it work. At least in case the original switch is not immediately available from dealer or if they for some reason charge too much for it or something.. (my local dealer has insane prices, depends on the country I guess )

 

I'm going to spray the switch with electrical contact cleaner in place. This is for state inspection which requires that switch to operate. The switch is available through aftermarket and is not expensive.
From the collective wisdom of Expy owners, what is the best way to get to the switch. Meaning what needs to be moved/removed for it appears to be buried ?

 

You have to remove the parking brake pedal assembly to be able to replace the switch.

 

Thanks alloro, this is what I suspected. The assembly I believe it's held in place by three bolts but how difficult is this to get to ?

 

See the attached procedure.

 

Ok, electrical contact cleaner didn't clean the switch up to work consistently to light the dash light. So, the next question is how much of the lower dash needs to come out to get the parking brake assembly out ?

 

I posted a PDF of the procedure up in my last post.

 

Yes alloro, that PDF does cover removing the e-brake assembly but unless I'm missing something (which I've done before) they do not cover what else needs to be removed to get to that assembly. I've included a pic of what I'm referring to.
In the attached pic, it shows that the lower panel has been removed but an electrical assembly and part of the dash (I suspect also needs to come out temporarily) so a be able to get to the bolt securing the switch. There is also a main wiring harness coming down the "A" pillar. The harness I suspect would not need to be removed, but the pic is to show how the switch is buried behind the infrastructure of the car.

Greg