I just picked up a 2001 Excursion to pull our Airstream trailer....

The switch on the dash to turn off the back alarm doesn't work, so I can't turn the alarm off when I'm backing up the trailer...a real PITA...! That constant ALARM is really distracting!!!

I can't find that system on a wiring diagram...

Any suggestions...anyone else have same problem?

I hate to disarm the system entirely, as it's useful at other times...

Thanks.

 

Are you talking about the "parking aid " system? I don't think it's a regular back-up alarm is it?

 

Ford calls it the 'Reverse Sensing System'....the gadget that 'beeps' when you back up near an obstruction....

 

The parking aid module is located in back on the passenger side panel in the cargo area, down low. If you have an aux heat/AC unit, it's underneath that. Then a wire runs from the parking aid module up the pillar to the speaker. The module is fed by fuse #28 in the underdash fuse box.

The switch looks like it connects a darkgreen/violet wire from the module to a resistor made into the switch, which then goes to ground.

Here's a excerpt from the service manual about the system. What I am wondering about is the wording in the lower part of the paragraph. It looks like if you push the button to defeat the system, and soon as you put it in reverse, it's going to re-activate. You will have to try it out and see how it works. If it's going to re-activate as soon as you go from drive to park when moving the trailer around, then the switch is not going to do you any good.

Principles of Operation

NOTE: The liftgate and back doors must be closed for correct operation of the parking aid system.

The parking aid system detects objects behind the vehicle when the vehicle is in reverse (R) gear. The parking aid module (PAM) does this by calculating the distance to an object by the use of four ultrasonic sensors mounted in the rear bumper. The ultrasonic field is emitted in a semicircular area around the rear of the vehicle. The sensors can detect objects approximately 1.8 m (5.9 ft) to the rear of the vehicle, 50 cm (1.6 ft) to the rear side of the vehicle. A 750 kHz variable warning tone is generated from a speaker located inside the RH cowl kick panel. The speaker increases its warning tone rate as the vehicle gets closer to an obstacle. When an object is detected within 25 cm (10 in) of the sensors, the warning tone becomes continuous.

The parking aid system is enabled when the vehicle ignition switch is in RUN and reverse (R) gear is selected. The parking aid disabled indicator will illuminate for three seconds when the ignition switch is turned to RUN. The system can be disabled by depressing the parking aid switch on the instrument panel. The parking aid system will indicate it is disabled by illuminating the parking aid disabled indicator (in the parking aid switch). The system will always enable when the ignition is turned to RUN, or when the vehicle is put into reverse (R) gear.

The parking aid system will be disabled if a fault is detected in one of the four sensors, the parking aid speaker or the parking aid module. This will be indicated by the parking aid disabled indicator being illuminated when the vehicle is put into reverse(R) gear. The PAM is on the International Standards Organization (ISO) 9141 network and can be diagnosed with a diagnostic tool.