Parasitic battery drain

G

Glenn-ho

New member
Anyone ever have a parasitic battery drain on there MM? went to start my mm and nothing not even a click even though it had a deltran battery tender. Though it was strange but battery was at least 4 years old and it would not charge so bought a battery. used it for two days and all good starting and charging. let it sit for three days with the battery tender and dead again. did a parasitic drain test and found it had a 1.6amp draw. No wonder battery tender could not keep up. Found when I removed fuse F1.114 which is a 30amp fuse hot all time fuse drain went away. Variable assist power steering(VAPS) module, Air suspension module, Air compressor relay, and instrument cluster. Pulled air compressor relay with fuse installed no change. will pull 1 connector at a time on suspension/vaps module to narrow it down. then if that doesn't work will pull cluster. Just wondering if anyone else seen this.
 
Strange. Early models of the S197 Mustangs had a similar situation that was related to the 'smart module'. This is the device that kept 'power on' to various accessories for up to a minute after the key was turned off. Disconnecting the battery negative first, positive last, fully charging the battery and reconnecting positive first, negative last, solved this issue in most cases (my Mustang was one of them). Another issue we had with this gen Mustang was the new gen radio wasn't shutting off when turning off the key, despite a blank display. Turning radio off manually before turning the key off solved most issues. With the Marauder? I dunno, as this is the first time I've read this.
 
Procedures are important. With the 2005 Mustang, 50ma is the highest parasitic draw allowed, after the car has been shut off for several minutes. Meter started off at 1.6a and gradually fell back. My Mustang was drawing 35ma the last time I checked.
 
could not work on the mm today. first thing I checked was the alternator. no am stereo. pretty sure it is in the circuit for that fuse.
 
Have same problem now, but found issue. Found out my air compressor was kicking on at random even when car been set for days. Then while putting ss brake notice driverside air bag had Deflated. Which i have notice compressor kick on alot while driving lately Spray soapy water on bag found air leak. So i recharged battery and switched off air ride for a week without drive her. Crank up fine Order new bag. Will put them on tomorrow. Switch air ride back on & 3 days later completely dead. Place a camera in garage that can be trigger by sound. Compressor kicked on at least 20time that day without me even touching the car.

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I pulled compressor relay and still have drain. thinking it is the air ride/vaps module. I can here a very light clicking from right side dash.
 
tried air ride switch before unplugging alternator. found when I unplugged vaps/air ride module drain went away. removed cover from module found burnt spot on circuit board.
 
Just so everyone knows the vaps and air ride worked. I have a NGS tester and there were no fault codes for either system. Only issue is battery drain.
 
FYI: All vehicles with a PCM have parasitic battery drain. Biggest reason why the vehicle needs a battery tender when sitting.
 
ty but guess you did not read my post. had a battery tender connected. 1.6 amp draw is way to high for a tender. should be .05ma or less.
 
Glenn-ho said:
ty but guess you did not read my post. had a battery tender connected. 1.6 amp draw is way to high for a tender. should be .05ma or less.
Click to expand...

Ya, that's too high. Put an amp gauge inline between Batt + post and + cable end and pull fuses 1 by 1 to locate the circuit that is drawing the power.

If it truly is the PCM pulling the power, that's odd but anything is possible. Someone around you with same MM/PCM code that you could swap to your car to see if it is the issue?

Good luck with the repair.
 
please read post before responding. l ready did a parasitic drain test. already pulled all fuses, F1.114 removed stopped drain. put fuse back in removed vaps/air ride module drain stopped. remove cover from module found burnt circuit board. ordered new module. will update after I install t.
 
I would have unplugged the ras vaps module and tested the power wire for short to ground and replaced its relay...
I just sold a used ras vaps last night on ebay, but its going to IA.
Bryan
 
I replaced relay made no difference. but when vaps/air ride removed and board inspected it is burnt. cannot upload photo.
 
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