Fuse 19 Airbag (Distribution Box) - Drain

[Flye]

1996 XLT, 4 DR., 4WD, 4.0L
Stock
No added systems for options
Owned Since new

NOTE: Edited to correct fuse. Original post for fuse designation for 19 was INCORRECT. This relates to the airbag system circuit.

-"Parasitic Power Drain" (Battery dropping over a week)
-Multimeter set up in line with negative cable
-System 'asleep'
-I've done far more extensive chase prior to finding this issue (found a few 1 or 2 mA issues, but the following is HALF of the drain, so I'm going to try to focus on this fuse/issue at this point.)
-Pulled Fuse #19 Airbag
(See J_C post below)
-Current drops from 88 mA to 44mA (to me, that is a HUGE drop and the 44mA is 'in range' for me)

I have no dash light for airbag if plugged in. If that fuse removed, with motor running, I get an irregular blinking airbag light on dash.

Anyone seen anything similar? What else can I check?

(Again this is Fuse in the UNDERHOOD DISTRIBUTION BLOCK.)

44 mA drain on fuse 19, 10 amp mini fuse shown below). Remove fuse, drain/current drops by 44 mA.

EDIT: Always subject to updating, but the ultimate 'diagnosis' was "AIRBAG CONTROL MODULE". After checking and unhooking all I could, swapped in a matching # module and drain went away. At this point I'm 'under spec', so going to give it a rest at this point.

Special Thank You to J_C for his help on diagrams and help.

Thanks for any help.

 

[J_C]

First let's be sure what is being looked at. You stated fuse 19, but I can't find a fuse 19. Here is what I see in the '96 owner's manual, which unfortunately does not number the fuses, but combine that with a picture provided by member 410Fortune (2nd picture below, which is for a 1997 but same older style pwr dist box so probably the same as a '96?), and the alternator fuse appears to be minifuse #6, is that the fuse you are referring to as #19?

 

[J_C]

I'm finding inconsistent info about fuse #'s as well. Here is a diagram that refers to alternator fuse as #17, and yet, I don't see a #17 either!

Alternator Circuit Diagram (1996-1997 4.0L Ford Explorer)

Ford 4.0L Index of Articles

troubleshootmyvehicle.com

 

[Flye]

Thanks. Indeed, I've found 3 sources online for 1996. First, Startmycar.com had it as Alternator, Another has it as airbag and yet a third has it as '4WD system'. I finally decided to check owner's manual and it has it as Airbag. I'll check that later in week to see if pulling the fuse to see if I get an airbag light on dash. Thanks for your help. IF I get a corrected dial in on what that fuse actually, I'm going to have to edit that original post to correct it. (I don't want that incorrect info out there for future searches.) Thanks again,

 

[Flye]

Pulling airbag fuse on 96 in distribution box gives me airbag warning light on dash, so feel like that is confirmation of 'airbag' and eliminate the others. Will change the original post since I don't want misleading info out there.

Any suggestions on how to sequentially find the drain in the airbag wiring schematic? My next step will be to disconnect, battery, remove driver airbag (that's the only one that has ever been out as far as I know) and see if I still get the drain. Beyond that, how would I test circuits or sensors to determine drain

Thank you,

 

[J_C]

See if you can find the schematic for the '96 airbag, possibly in that PDF I sent you, and post that to view or at least LMK the page #. Otherwise I can make vague reference to other airbag circuits for 2nd gen.

I don't know what you mean by "that's the only one that has ever been out"? Do you mean deployed during an accident, or removed to do a repair, or? Certainly, disconnecting vehicle battery for a minute, then disconnecting the driver's steering wheel airbag is something to try. Possibly it has a leaky capacitor in it or something, or the wires in the steering column are shorting somehow but I'd think that would make the drain more intermittent?

Does a '96 have a passenger side airbag? If so then check it next, though I'm not sure of the best way to access it besides pulling the glovebox out to take a look. Once those are out, it appears that each airbag uses two wires going to the "air bag diagnositc monitor" (?) IDK if I've ever encountered anyone having to check that, don't know where it is, but you could check for shorting between those two wires going to each airbag, and that neither is shorting to ground... or does the air bag diagnostic monitor short one to ground in the passive state? I don't know.

If that checks out, unplug the air bag diagnostic monitor to see if the parasitic drain goes away without it plugged in.

Obviously the below schematic is not entirely correct as it shows Fuse 5 for airbags, which is consistent with what my owner's manual shows for my '98 though I don't have any other evidence of which model years this schematic applies to.

 

[Flye]

"that's the only one that has ever been out" << Sorry! means, it has been out of the steering wheel to change the cruise switches. Never had a collision release.

 

[Flye]

Final Conclusion: Always subject to updating, but the ultimate 'diagnosis' was "AIRBAG CONTROL MODULE". After checking and unhooking all I could, swapped in a matching # module and drain went away. So it appears airbag control modules do give issues from time to time.

At this point I'm 'under spec', so going to give it a rest for a while.

Special Thank You to J_C for his help on diagrams and help.