Battery drain

Ray Diagnostician North York, Ontario Posted   Latest   Edited  
2011 Ford Escape Limited 3.0L (991) 6-spd
Parasitic Load

I was asked to diagnose a battery drain on a 2011 Ford Escape 3.0 and the first thing that I noticed was the rear wiper arm was at the 12 o'clock position.


CH A is the battery voltage

CH B is the amp clamp on the negative battery cable. The module is staying awake and it's trying to park the rear wiper arm. The rear wiper motor draws 6.4A for 7 seconds, then the module waits 27.61 seconds before it tries to park the wiper arm again. 

Near the end of the capture, I pulled the 2 rear wiper fuses. 

Chris Diagnostician
Bryans Road, Maryland
Chris Default

Nice find as always Ray. Always a good idea when looking for a draw to do a initial check over of the vehicle to see if any lights or anything else sticks out that are out of the norm!

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Geoff Diagnostician
Lahaina, Hawaii
Geoff Default

Wow, great catch Ray. Having never had a single customer complaint about a rear wiper (or defroster...LOL) I forget those even exist. Thank you for the reminder.

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Ray Diagnostician
North York, Ontario
Ray Default

You're welcome Geoff!

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Frank Owner/Technician
Toronto, Ontario
Frank Default

Well done Ray! A great catch but honestly would expect nothing less.

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Samuel Technician
Somers Point, New Jersey
Samuel Default

This is a GREAT find. You make it sound simple. We should keep it simple and look for the obvious....I have said in other posts, "avoid the wormhole" or "chasing a ghost". Many times over I feel we want it to be a complicated diagnosis to test ourselves. Realistically, you handled this PERFECTLY!!!!!!!

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Ray Diagnostician
North York, Ontario
Ray Default

Thank you!

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Billy Mechanic
Deming, New Mexico
Billy Default

Good job I learned about rear wipers when in my cockiness I declared a BCM on a Chevy and it turned out to be the rear wiper motor stuck tripping the circuit breaker boy was I red faced but never made that mistake again

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