Brake light switch and shifting issues

[blacktail]

I have a 2006 Expy with Eddie Bauer and tow package and am currently towing a travel trailer across the country.

Yesterday, a helpful stranger alerted me that my running lights were working, but brake lights were not.

I checked all fuses, which were ok. So, I turned on my hazards and drove to nearby auto parts store. Discussed problem with manager who speculated that the brake light switch might be bad. So, I replaced, and that seemed to fix the issue.

Drove another 300 miles today with brake lights working fine, but now I am having a different problem that seems to be related to the switch.

After starting the vehicle, foot on the brake with lights on, it won’t shift out of park. “Wiggle” the brake light switch a little up or down, and I can shift out of park. There is an audible “clicking” sound when I wiggle the switch.

Depending on how I position the switch with a wiggle, the brake lights will work and I can’t shift out of park, or, shifting is easy but no brake lights.

So, I can wiggle the switch to shift, then wiggle again to get brake lights and drive fine. I can also use the button under the steering column to override the shift lock.

While this is somewhat of an interesting anti-theft situation, I would like to repair whatever is really at issue here.

Did I install the switch incorrectly? I am putting the bushing on the before installing the switch if that makes a difference.

I see alot of threads related to this issue referencing videos, but I have not seen a video that solves my issue. If someone could link to the relevant video I would appreciate it.

My family is in the car with me so I want to make sure it works.

Thanks in advance.

 

[sjwelds]

I would suggest a motorcraft switch for a start.

 

[Hamfisted]

What brand is the one you bought ? Autozone's Duralast is usually serviceable but if you have the option I would stick with Motorcraft as well. You got a solid connection with the plug right ? If you have the ForScan app on your phone or laptop you can look at the brake switch PID and see if it is actuating when you step on the pedal or not.

Motorcraft Expy Brake Switch at Rock Auto ( SW6239 )

Motorcraft SW6239 Brake Light Switch on Amazon










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[blacktail]

Thanks for all the replies everyone. I believe I solved the issue.

Because this is a pressure switch, the position and angle if the switch relative to the plunger rod is paramount.

You can notice that the wiring harness has a slight curve to it. If this is not looped around the black cylinder (power steering associated?) there is tension on the wiring harness and the brake switch will not function properly.

I had not been arranging the wire harness properly. Once I did all was well.

See attached photo.

I believe the harness can be put out of place during a hard braking incident or if your foot slips “up” and rubs against it.

I hope this information helps anyone who comes across this thread.