1996 Ford Ranger battery drain

Tiny
RESQ12345
  • MEMBER
  • 1996 FORD RANGER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 100,023 MILES
I have a 1996 Ranger with a consistent battery drain. I have ruled out both the battery (by replacing multiple batteries) and the alternator (by having tested). Here is what I have observed so far. When I place an ammeter in line with the neg battery terminal and neg battery post, with the doors all closed, and before the GEM shuts down, I am showing.23 amps. When the GEM shuts down after 40 minutes or so, the current reading goes down to.15 amps. Now I start pulling fuses. (I use a screwdriver to close the door latch so I can get at the fuse box with the door open.) When I come to the large fuse in the main fuse box under the hood labled FUEL SYSTEM / ANTI THEFT SYSTEM and pull it, the current reading goes down to.05 amps (which is considered normal by ford standards). I have read that there is a TSB from ford regarding fuel pump and ecm relays sticking and causing a batery drain, so I replaced these relays, with no luck. I can't hear the fuel pump running, nor does there seem to be any problems with my factory antitheft, although I have no idea where the module is to disconnect it. One thing I did notice is that my gas gauge stays put (energized?) With the ignition off. I have no idea what else to check. Someone please help before I pull out all of my hair.
Wednesday, July 8th, 2009 AT 2:02 PM

9 Replies

Tiny
BUDDYCRAIGG
  • MECHANIC
  • 2,262 POSTS
I'm looking at your schematic.
And fuse #12, a 20 amp MAXI fuse
goes straight to the fuel pump relay.

If you unplug the relay and the draw is still there, then it has to be the RAP module.

There is only one connection between the fuse box and the RAP, and that is directly at the RAP (C409). So I would assume that it has to be close to the fuse box.
I'll keep looking for a location for you.
Was this
answer
helpful?
Yes
No
Wednesday, July 8th, 2009 AT 7:03 PM
Tiny
BUDDYCRAIGG
  • MECHANIC
  • 2,262 POSTS
It says, left rear corner of cab,

I'm still looking for a picture.
Was this
answer
helpful?
Yes
No
Wednesday, July 8th, 2009 AT 7:05 PM
Tiny
BUDDYCRAIGG
  • MECHANIC
  • 2,262 POSTS
No picture.
But it says module is located behind trim panel at driver-side B pillar.
Disconnect negative battery cable, unplug 22 pin connector first, then 26 pin connector.
Was this
answer
helpful?
Yes
No
Wednesday, July 8th, 2009 AT 7:13 PM
Tiny
RESQ12345
  • MEMBER
  • 3 POSTS
I found the RAP module and disconnected it and the current draw went away. My question is: what SHOULD be the correct current draw? I have had no problem with the anti theft system. Also, could a remote relay be causing the drain? I would prefer to replace a relay first before replacing the RAP
Was this
answer
helpful?
Yes
No
Tuesday, July 14th, 2009 AT 6:49 PM
Tiny
BUDDYCRAIGG
  • MECHANIC
  • 2,262 POSTS
Sorry, I dont have any books that will tell me that.

About the what else it could be.
You have a solid state electrical device that has freaked out. It could be anything.

But this might help trace things down.
As a test, only plug in the 22 pin connector and see if you still have the draw.

Then we'll chase down those wires.
Was this
answer
helpful?
Yes
No
Tuesday, July 14th, 2009 AT 10:49 PM
Tiny
RESQ12345
  • MEMBER
  • 3 POSTS
Hi,

Thanks for all your guidance so far.

I disconnected the 22 pin connector and the draw went away. There only seems to be 7 or 8 wires in the whole connector, so can't be too many more things.

Is it possible I could get a look at whatever wiring diagram you are looking at as well?

Thanks again!
Was this
answer
helpful?
Yes
No
Wednesday, July 15th, 2009 AT 11:21 AM
Tiny
BUDDYCRAIGG
  • MECHANIC
  • 2,262 POSTS
I wanted you to have the larger plug already unplugged, and see if you have the draw with only the 22 pin connector plugged in.

That way we know it has nothing to do with the large plug and we only have to deal with those few wires.

And yes, i'll get you a schematic this evening when I have access to that computer.
But the pictures will be big, so i'll have to email them to you.
Was this
answer
helpful?
Yes
No
Wednesday, July 15th, 2009 AT 12:43 PM
Tiny
DONNA EXUM
  • MEMBER
  • 2 POSTS
All of these sound good but my truck battery does not die it just loses power and battery light comes on. My radio comes on randomly without me turning it on and sometimes when I give it has the lights dim
Was this
answer
helpful?
Yes
No
Thursday, January 12th, 2017 AT 4:57 PM
Tiny
CARADIODOC
  • MECHANIC
  • 34,073 POSTS
You need to start a new question, and please be sure to list the engine size and mileage. Also include any tests that were done already and the results. You have a different problem. This question is a conversation between only two people. None of the other experts will see it or have a chance to respond. That does you a disservice. If you post your question within the next 30 minutes, I'll see it and reply. Otherwise I might see it tomorrow if no one else has replied by then.

If you want to start the testing, measure the battery's voltage while the engine is running. It must be between 13.75 and 14.75 volts. List what you find. That will determine where we go next.
Was this
answer
helpful?
Yes
No
Thursday, January 12th, 2017 AT 5:50 PM

Please login or register to post a reply.

Related Battery Drain Content

How to Test for a Battery Drain-Draw
VIDEO
How to Test for a Battery Drain-Draw
In­struc­tional re­pair video
Battery Parasitic Drain Repair
GUIDE
Battery Parasitic Drain Repair
A car bat­tery should hold its charge for a few months be­fore need­ing to be recharged, if not the bat­tery has gone bad or the car has a par­a­sitic draw, some­thing is stay­ing ...
VIEW MORE