Mechanics

BATTERY DRAIN

1996 Ford Ranger

Electrical problem
1996 Ford Ranger 6 cyl Four Wheel Drive Automatic 100023 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.
Avatar
Resq12345
July 8, 2009.



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.

Buddycraigg
Jul 8, 2009.
It says, left rear corner of cab,

I'm still looking for a picture.

Buddycraigg
Jul 8, 2009.
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.

Buddycraigg
Jul 8, 2009.
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

Tiny
Resq12345
Jul 14, 2009.
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.

Buddycraigg
Jul 14, 2009.
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!

Tiny
Resq12345
Jul 15, 2009.
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.

Buddycraigg
Jul 15, 2009.