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02 F250 7.3 6 speed
Leaving for work this morning and parking brake light switch is stuck in the brake on position. Parking brake itself is working correctly. I get to work and look under there it appears the plug was loose on the switch. I think I solved the problem but don’t know for sure until I drive the truck for awhile. I have a 3 hour drive this afternoon.
Looks like a hard to replace switch if necessary. Don’t know whether it’s normally open are normally close switch can it be jumper it out if necessary.
Thanks Joe
Y2KW57 has a documented fix action for the design failures of the switch. His fix action worked for me for a while, but not long term. I ended up using some solid core copper telephone wire in order to make my own fix for the switch shortfalls. It has been good for a few years now and I don't plan to even look at it sideways until it stops working, if it stops working.
Your first course of action should be what the fellas above recommended before going "armchair engineer" on it like I did.
I appreciate the input.
It appears I have solved the issue, the plug was loose at the switch. Been driving a lot yesterday and today and it’s working fine.
Have not found info on how to replace the switch, if that is needed in the future.
The video below shows how to replace the switch by removing the bolt toward the top and firewall. He does not actually remove the switch, but talks about the process which is very quick and painless.
There is a contact plate on top of the plunger. This plate is shaped like a small washer, with the plunger head captured in the inside diameter, and with the broad flat of the washer being the ground contact surface. The contact washer is wobbly. I found a tiny rubber foot lying on the workbench, so I shoved it over the tip of the plunger pin, so that the rubber would stabilize the wobbliness of the contact plate washer.
Very hard to explain, and I deleted the pics in the write up I made of the process, but after stabilizing the contact washer, the parking brake engagement light worked much more reliably ever since. I needed it to work in order for the APCM to work.
Picture of random rubber tip I had on hand, as mounted on top of parking brake switch under the dash.
Originally Posted by NumberDummy
F2UZ-15A851-A .. Park Brake Warning Light Switch / Available from Ford.
About a year later I need to perform a similar mod as Y2KW57 has done. The entire parking brake assembly and switch are brand new. The switch itself is a well designed POS and needs a bit of improving even when new.
The Y2KW57 method is on my list of things to get done over the next few weeks while the truck has a space in the garage.
Originally Posted by Y2KW57
Finally found a couple of my old pics to help you out, Sous. I know how you love pics.
Before:
After:
What the rubber "tit" does is simply stabilize the contact washer, so that it both lands on and departs from the two vertically oriented contact bars evenly. Prior to the rubber stabilizer, the contact washer could get cockeyed on the spring loaded shaft, due to the inner diameter of the washer being larger than the diameter of the shaft, which gives the washer room to wobble and shift about.
The pointy part of the rubber piece is unnecessary, and could be cut off. I left mine on as a "handle" to more easily remove the rubber piece in the event that the modification was not successful, however, I have not had any issues with this switch since performing this mod several years ago.
Something else could work just as well. For example, if the swedging at the washer end of the shaft were more pronounced, the washer might be stabilized in that manner. Again, I just looked around on my messy workbench and spied that piece of rubber, noting that it had a very small diameter indent on the broad disc end that would "hug" the swedged end of the shaft tightly, and thus maintain the washer in a horizontal position throughout it's spring loaded jolt of travel.
If you look carefully, you will note that the shaft actually has two different diameters... the main diameter covers the majority of the shaft, and a necked down diameter about which the contact washer is positioned. There is simply too much of an area where the shaft is necked down. While I no longer have access to a physical switch in my hand (I'm not taking mine out again as long as it keeps working), I have given some thought as to what other types of commonly available parts could be used to reduce the axial play. One such thought that occurred to me is using a tiny diameter "E" clip between the washer and the swedged end of the shaft. I haven't tried it, but it would be one of the things I would try if I hadn't stumbled across the rubber thing that I used.
To date (5 years later), I've not had any problems with the parking brake switch since performing the modification above. My switch is still original, now over 21 years old (November 1999 build date).
I never use my park brake on my zf6 truck anymore.
I installed a line lock to the rear calipers.
Holds 18k easily on steep inclines. Simple. Never had an issue in years. When plowing/cindering I use it upwards of 75+ times per day. Will stay in N and lock it on a steep hill loaded, climb on top of truck to break up frozen cinders, that is how much it can be trusted. https://zips.com/parts-detail/mico-e...rak-02-620-009
I never use my park brake on my zf6 truck anymore.
I installed a line lock to the rear calipers.
Holds 18k easily on steep inclines. Simple. Never had an issue in years. When plowing/cindering I use it upwards of 75+ times per day. Will stay in N and lock it on a steep hill loaded, climb on top of truck to break up frozen cinders, that is how much it can be trusted. https://zips.com/parts-detail/mico-e...rak-02-620-009
And I thought I was the only one that climbs in the back of his truck all the time...
Just replace it with one of these guys: 2L2Z-15A851-AA
Way better design.
I agree that the 2L2Z-AA switch is a better design. The top part of the moving pin is guided by an enclosed column/tower at the top of the switch, which keeps it perpendicular, and thus keeps the contact plate from hanging up.
Has it been verified that the 2L2Z will interchange with the XC2Z?
You've installed the 2L2Z in your 99-03 Super Duty without issue?
I agree that the 2L2Z-AA switch is a better design. The top part of the moving pin is guided by an enclosed column/tower at the top of the switch, which keeps it perpendicular, and thus keeps the contact plate from hanging up.
Has it been verified that the 2L2Z will interchange with the XC2Z?
You've installed the 2L2Z in your 99-03 Super Duty without issue?
Not direct plug and play. It uses a different wiring connector and the ground connection is not made through the mounting screw. I got mine from a scrap truck so I got the connector as well. So anyone wanting to do this upgrade would want to acquire a wiring connector with it as well.
As you mention, the enclosed design increases the reliability, since the contacts are protected from the elements, particularly dirt, snow and road salt that tend to come in the cab on my boots.
I never use my park brake on my zf6 truck anymore.
I installed a line lock to the rear calipers.
Holds 18k easily on steep inclines. Simple. Never had an issue in years. When plowing/cindering I use it upwards of 75+ times per day. Will stay in N and lock it on a steep hill loaded, climb on top of truck to break up frozen cinders, that is how much it can be trusted. https://zips.com/parts-detail/mico-e...rak-02-620-009
That is a nice looking product. If I needed to use it as much as you do, I would be on that, given the relatively weak factory parking brake holding power.
My switch has not been reliably making contact when the parking brake pedal is pushed. Pulled it today and now I can see why. Lots of accumulated dirt.
The tab to wire connection was pretty clean, but I found dirt on the two contact blades, under the washer, and some corrosion between the washer and the shaft, and on the mounting screw location. I think any of those spots could break the ground connection the dash light is looking for.
Some 1000 grit sandpaper slid between each of the contact plates and the washer, cleaned them up. Flipping the sandpaper over and repeating cleaned up the underside of the washer. I chucked up the shaft in the drill and spun it slowly while holding the washer to clean up the corrosion between them.
Installed now and seems to be working well. In my case, I don't think the floppy washer was as much the issue, as making sure each contact point in this little switch is clean.
