When I place the shift lever into reverse, the backup sensors automatically turn off? If I put the shifter into park, I press the button so that "off" is no longer illuminated, but then as soon as I hit reverse again, it turns off. Any ideas what's going on with this?

 

I assume the sensors are not working. The light on the button did that when mine were not working ( I had one bad sensor). You have to figure out if you have a bad sensor or if the speaker is not working( this also breaks the circuit).

 

Like Mattb said, it sounds like the system is detecting a fault - I had the same thing, I started off replacing the speaker as there wasn't any sound at all - when I replaced the speaker I then heard one short bleep when I selected reverse, but it would then turn off again - I then found one of the sensors was faulty, so I replaced the sensor and everything works well now.

 

Awesome, thanks! I assume the speaker is located in the dash? Is there a way to test the sensors, or should I just buy on and then swing test them until I find the bad one?

 

On both my Expedition and Excursion, the speaker is in the rear cargo area - My Excursion speaker is on the rear passenger side pillar (there are small holes to let the sound out) and the speaker is a small round and black (probably about 2" diameter)

Someone else will probably have a better way to test the sensors, but I just felt each one for a ticking feel (with the truck key on engine off and in reverse) and you can also use a stethoscope to listen to them. If you find one that is faulty, check the plug and wires before buying a new sensor as they do collect a lot of dirt!

 

That's great info, will get out there sometime today and check it out. Being a lifted truck with plenty of blind spots, that seems like it would be a very useful tool, besides, its there already, why wouldn't I want it to work? Thanks for the help!

 

talk about a can of worms.....I opened up the right rear panel, the harness isn't plugged into anything! So, now I am going to try and reroute it and plug in all of the connectors and see what happens. This is all a part of buying a used vehicle I guess.

 

If you have an AE or good scanner, it will tell you which sensor is bad, or in my case give me the fault code that tells you which is not working.

 

Can someone post where the sensors can be bought? Mine hasn't worked since I bought it.