How to find parasitic draws on known circuits
I have a 2009 Ford Escape Hybrid. For months now we have been trying to fix a PATS issue that stops the car from starting. Fixing the problem is even more difficult due to parasitic draws that keep killing the battery. I have a .35amp draw on fuse #5 (BSI, SPDJB, & Keypad; this model has no keypad and I don't think the CVTs have a BSI), .2amp on fuse #14 (front display module, radio, satellite), .2amp on #15 (climate control), and .6amp on fuse #26 (instrument panel cluster). Now that I know the circuits, how do I find the exact source of the problem? Every tutorial video I find stops at identifying the fuses. Are these normal draws if the vehicle isn't asleep? Is there a way to tell if the vehicle is asleep or not?
Just about all go into sleep mode in 45 minutes to an hour.
Keep in mind most vehicles allow 50 milliamps drain and is considered normal, although best to refer to manufacturer's spec.
Alternator, clock, various memory banks are figured into this figure. Anything over that amount deserves further investigation.
There is a special procedure to find parasitic drains, some of which include measuring voltage drop over fuses. Once you pull the fuse of the questionable circuit power is cut and the module resets, so when you put the fuse back it will not show any drain.
The driver's door has to remain closed if the fuses you are checking are inside.I think you now get the picture as to why not a lot of people want to get involved checking voltage drop over fuses.
Keep in mind most vehicles allow 50 milliamps drain and is considered normal, although best to refer to manufacturer's spec.
Alternator, clock, various memory banks are figured into this figure. Anything over that amount deserves further investigation.
There is a special procedure to find parasitic drains, some of which include measuring voltage drop over fuses. Once you pull the fuse of the questionable circuit power is cut and the module resets, so when you put the fuse back it will not show any drain.
The driver's door has to remain closed if the fuses you are checking are inside.I think you now get the picture as to why not a lot of people want to get involved checking voltage drop over fuses.
Thanks for the response. I had engaged the driver's door latch with a screwdriver, but opted to rerun the test with the only the passenger door open this time. It worked! No parasitic draw. Now on to trying to do a PATS relearn with Forscan. Thanks again for responding.
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Paxonator
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Oct 12, 2018 10:38 PM



