Rear wiper and hatch lock issues

[beeman]

My 2016 fiesta has been acting weird in regards to the rear hatch. The rear wiper and rear fluid sprayer both have stopped working entirely, and the hatch lock has been difficult.

If it rains, the hatch lock will unlock when certain lock signals activate, (the automatic one once you get up to speed and locking from the key fob sometimes), and work normally with others.

The rear wiper and washer sprayer don’t work at all

I’ve already replaced the battery so I know it’s not something with that. I want to see if anyone else has encountered weird issues with the hatch electronics and if replacing the rear wiper motor and hatch lock would fix the issues.

 

[anxiouz]

There is a fuse for the rear wipers that you can check in the passenger footwell, but since the fluid and latch are also having issues, I'd prob check the wiring between the hatch and the car. It's not uncommon for the wiring going through the rubber connector tube from the hatch to get crimped or damaged over time. Might we worth loosening the rubber grommets and wiggling the wires there to see if anything changes (or if any have too much play and might be loose).

It's also easy to take off the inside plastic cover of the hatch to see how the wires and connection to the hatch look too.

 

[Intuit]

All rear lights work'n okay? (turn, reverse, running, brake)

Does your FRONT sprayer work? If the FRONT does work, the hose for your rear is probably disconnected and could be spraying fluid into the passenger cabin. This may occur during headliner removal/install. Sometimes people just forget to reconnect the hose. If you do NOT hear the washer pump and it is not working for only the rear then it has to be the switch on the stalk.

In addition to what @anxiouz mentioned, check for codes. Confirm whether power is leaving the BCM. Confirm whether it is reaching the wiper motor. (more convenient to check at connector points) Check for shared ground point. "Voltage drop testing" while a circuit is fully loaded can help you identify the existence of connection(s) with insufficient load. You can verify signaling by poking a straight-pin through wiring and connecting to volt meter.


From personal experience, LED lights that have the built-in load resistors can go bad; dump load off to ground that interferes with BCM function. So if the issue only seems to be present, intermittently, when the lights are active, disable or remove those lights then test again.


NOTE: I seriously doubt we have the rain sensing module cause Ford cheaped out on features for us 'meriguns.