2006 f350. Whenever it rains my parking aid off light will come on while driving. Sometimes I can turn it back on by pressing the botton. I have tried spaying things with a garden hose to duplicate, but I can't make the light come on. Anyone one have simular problem? I tried searching but nothing like this comes up.
Thanks

 

Water or corrosion is likely getting into the connectors at the back bumper or where the bumper harness hooks into the chassis....start looking there.

 

Here's a link that might help. Talks about the connections, corrosion, or moisture in the sensor (use a hair dryer)

Ford Excursion Reverse Sensing System

 

This happens when you get a crack in your sensor.

 

Checked for cracks, all of them look fine. Checked and all the sensors are working. Flooded both sides of the sensors with water from a garden hose, still working fine. What is different than most of the problems others have is the "off" light comes on while I am driving, not when backing up.

 

I think those sensors actually made a faint click sound when the vehicle was in reverse. No click means a bad sensor. There is a PAM, park aide module, some place in your truck. It's job is to communicate with the sensors. If the PAM has issues with sensors it will just shut down, giving you the off message on your display.
Those early sensors were trouble prone. You could probably find a new set of Ford sensors on eBay for less than $100. They are very easy to replace.

 

They all make the clicking noise when trans is in R. And the system is working right now. Need to find the PAM and see if it could be getting wet.

 

PAM is/should be under the dash. Doubt it got wet. If you have not found any faults back at the bumper and where the bumper harness connects to the chassis harness by the spare then follow the wire loom into the cab. The PAM will be at this end. You could have a bad PAM. Might be worth a trip to the stealership to have that system read. Note if you need a new PAM I think you need to have the dealer force feed the new code in. On my 11 you cant just plug in a new PAM.