2000 Ford Ranger XLT battery parasitic drain issue.

[Brock]

My Problem:
I have found a parasitic drain that led to fuse #26. With fuse #26 plugged in, I'm getting (-2.20mA) --> (-2.30mA) jump every 3-4 seconds. With fuse #26 unplugged, I'm getting (0.02mA) which is normal, I think.
I isolated the drain by pulling fuses to the GEM module as well as my radio and possibly some unknown thing.
The GEM module was draining (-2.11mA) with the radio pulling out around (0.09mA)
When both GEM module and radio are disconnected I have a (0.08mA) drain that jumps up to (0.20mA) about every 3-4 seconds. (this only happens when fuse #26 is plugged in)
I have found that no matter what I do, as long as fuse #26 is unplugged, my draining milliamperage will go to normal levels (0.02mA).
Fuse #29 pertains to the radio and drops the milliamperage from (0.09mA) --> (0.02mA) when unplugged. (fuse #26 is plugged in, fuse #29 is pulled out)
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My question is this:
1)What could cause the (0.08mA) --> (0.20mA) spike every few seconds? (The drain I haven't found)
2) What are the chances replacing the GEM will fix the big drain?
3) What are the chances replacing the radio will fix the small drain?
4) What other ways could I fix this?
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Possibly useful information:
Fuse #29 is radio only.
Fuse #26 includes:
Battery Saver Relay, Electronic Shift Relay, Interior Lamp Relay, Power Window Relay, Electronic Shift Control Module, Dome/Map Lamp, GEM, Instrument Cluster


I'll answer questions as fast as I can.
Please help and thank you.

 

[RonD]

I think you have you amps and milliamps confused, 0.02 amps is 20milliamps

1995 and up Ranger should have a draw of 0.04 to 0.07amps(40-80mA) when key is off and doors are closed
Radio and computer draw about .02amps, anti-theft .02, Keyless entry .03
Keyless entry needs to be listening all the time

BUT................1995-2003 have a GEM module that "stays awake" for about 20-30min after key is off and doors are closed
THEN is goes to sleep
Which makes finding a drain a PITA
Pulling fuse 26 puts GEM to sleep right away, but if drain is from a GEM controlled device, then..............PITA

First, thing if you think there is a drain is to test battery
Unhook either battery cable after you get home, test battery voltage, write it down
6 hours, or longer latter, re-test battery voltage, should be EXACTLY the same
Don't care if "its a new battery" TEST IT
Battery can be self draining, after 5 years or so, OR when NEW

If battery tests OK
Hook up amp meter then wait 20-30min for GEM to go to sleep
If amp draw is more than .08 after that then you have a drain

See if the "Spike" happens when THEFT light flashes, I think its every 5 seconds or so
I don't think Keyless entry would "spike"

 

[Dirtman]

To add to what Ron said, at least on my truck taking an amp reading via disconnecting a terminal and connecting a multi meter will "wake up" the stupid computer even if you wait so you always end up with a false reading.

To do it without waking the computer up you need to disconnect the negative terminal and connect a jumper wire between the cable and terminal. Then connect your multi meter separately between the cable and terminal. After 30 minutes with your multimeter still on and reading amps disconnect the jumper wire so everything is running through the meter. This won't disrupt the computer but still allow the meter to read amp draw with the computer in bed time mode.

 

[Brock]

I think you have you amps and milliamps confused, 0.02 amps is 20milliamps

1995 and up Ranger should have a draw of 0.04 to 0.07amps(40-80mA) when key is off and doors are closed
Radio and computer draw about .02amps, anti-theft .02, Keyless entry .03
Keyless entry needs to be listening all the time

BUT................1995-2003 have a GEM module that "stays awake" for about 20-30min after key is off and doors are closed
THEN is goes to sleep
Which makes finding a drain a PITA
Pulling fuse 26 puts GEM to sleep right away, but if drain is from a GEM controlled device, then..............PITA

First, thing if you think there is a drain is to test battery
Unhook either battery cable after you get home, test battery voltage, write it down
6 hours, or longer latter, re-test battery voltage, should be EXACTLY the same
Don't care if "its a new battery" TEST IT
Battery can be self draining, after 5 years or so, OR when NEW

If battery tests OK
Hook up amp meter then wait 20-30min for GEM to go to sleep
If amp draw is more than .08 after that then you have a drain

See if the "Spike" happens when THEFT light flashes, I think its every 5 seconds or so
I don't think Keyless entry would "spike"

0.02 amps, got it. It is a new battery but I'll have to test the battery tomorrow and I'll see what it does.
I think my GEM module should only wake up when I turn my truck on because I severed the wires that connect to the door latch.
The dome lights wouldn't turn off so I put the wires to death.

As for the GEM device, I think the PITA option is the most likely.
What do you think about the radio and do you know how I can narrow it down from the GEM module?
I don't have keyless entry. I was looking at the anti-theft light to see if it spiked with it but it didn't seem like it. I'll double check.

 

[Brock]

To add to what Ron said, at least on my truck taking an amp reading via disconnecting a terminal and connecting a multi meter will "wake up" the stupid computer even if you wait so you always end up with a false reading.

To do it without waking the computer up you need to disconnect the negative terminal and connect a jumper wire between the cable and terminal. Then connect your multi meter separately between the cable and terminal. After 30 minutes with your multimeter still on and reading amps disconnect the jumper wire so everything is running through the meter. This won't disrupt the computer but still allow the meter to read amp draw with the computer in bed time mode.

I'll try that.

 

[Brock]

I think you have you amps and milliamps confused, 0.02 amps is 20milliamps

1995 and up Ranger should have a draw of 0.04 to 0.07amps(40-80mA) when key is off and doors are closed
Radio and computer draw about .02amps, anti-theft .02, Keyless entry .03
Keyless entry needs to be listening all the time

BUT................1995-2003 have a GEM module that "stays awake" for about 20-30min after key is off and doors are closed
THEN is goes to sleep
Which makes finding a drain a PITA
Pulling fuse 26 puts GEM to sleep right away, but if drain is from a GEM controlled device, then..............PITA

First, thing if you think there is a drain is to test battery
Unhook either battery cable after you get home, test battery voltage, write it down
6 hours, or longer latter, re-test battery voltage, should be EXACTLY the same
Don't care if "its a new battery" TEST IT
Battery can be self draining, after 5 years or so, OR when NEW

If battery tests OK
Hook up amp meter then wait 20-30min for GEM to go to sleep
If amp draw is more than .08 after that then you have a drain

See if the "Spike" happens when THEFT light flashes, I think its every 5 seconds or so
I don't think Keyless entry would "spike"

I tested it. At 10:18 on 8/7/2021, my battery with only the positive terminal connected had a voltage of 12.68V.
I tested the battery 6 hours later. At 16:21, it was coming out as 12.68V, the same as 6 hours before. The battery seems to be fine.

 

[RonD]

Yes, battery is good

 

[Brock]

Yes, battery is good

Do you know where I should start to find the drain from the GEM module? Any highly suspect electronics? Maybe the GEM itself?

 

[RonD]

Not sure its from GEM module

I will post the 4 drawings I have for 2000 Ranger power distribution
Diagrams have BOTH types of systems, WITH power windows/locks and W/O
So pay attention

Key off, doors closed

Hook up amp meter

Start in engine fuse box(battery box), most of these have full time power, which is what you want
Many of the Cab fuses(central box) are Key on power so not the problem

The Computer(fuse 6 in engine box) and radio(fuse 29 in cab box) have full time power to hold memory, clock and presets, they pull about 0.03amp
I would pull both those fuses before you start, then you are just getting keyless entry, anti-theft and "the drain"

Fuse 1 in engine fuse box powers a whole bunch of Cab box fuses(page 2), including GEM fuse 26
Pull it and see if amps drop close to 0

 

[Brock]

Not sure its from GEM module

I will post the 4 drawings I have for 2000 Ranger power distribution
Diagrams have BOTH types of systems, WITH power windows/locks and W/O
So pay attention

Key off, doors closed

Hook up amp meter

Start in engine fuse box(battery box), most of these have full time power, which is what you want
Many of the Cab fuses(central box) are Key on power so not the problem

The Computer(fuse 6 in engine box) and radio(fuse 29 in cab box) have full time power to hold memory, clock and presets, they pull about 0.03amp
I would pull both those fuses before you start, then you are just getting keyless entry, anti-theft and "the drain"

Fuse 1 in engine fuse box powers a whole bunch of Cab box fuses(page 2), including GEM fuse 26
Pull it and see if amps drop close to 0

Thanks for the wiring diagrams. I'll try that out tomorrow morning and see what happens.

 

[Brock]

Not sure its from GEM module

I will post the 4 drawings I have for 2000 Ranger power distribution
Diagrams have BOTH types of systems, WITH power windows/locks and W/O
So pay attention

Key off, doors closed

Hook up amp meter

Start in engine fuse box(battery box), most of these have full time power, which is what you want
Many of the Cab fuses(central box) are Key on power so not the problem

The Computer(fuse 6 in engine box) and radio(fuse 29 in cab box) have full time power to hold memory, clock and presets, they pull about 0.03amp
I would pull both those fuses before you start, then you are just getting keyless entry, anti-theft and "the drain"

Fuse 1 in engine fuse box powers a whole bunch of Cab box fuses(page 2), including GEM fuse 26
Pull it and see if amps drop close to 0

(Unless Maxi-Fuse #1 was in, all of these numbers would have been (0.00A).)
With Maxi-Fuse #1 pulled, my multimeter was reading (0.00A). Just like you said.
With engine bay mini-fuse #6 pulled, it read (2.09A) and spiked up to (2.26A) every 3-4 seconds.
With both E.B mini-fuse #6 & fuse #29 pulled, I was pulling (2.00A) and spiking up to (2.14A) every 3-4 seconds.

I still think it has something to do with the GEM module and my radio.
If not that, something coming off my GEM module.

 

[Brock]

Note that when I disconnect my GEM and radio completely and put all fuses in, I'm still getting a (0.08A) -> (0.12A) spike every few seconds.
That is from (0.00A) btw.

 

[Roert42]

You ever ever find anything @Brock ?

 

[helpme]

What keeps the gauges from going to zero when the truck is switched off. Is that power coming from the GEM too? Thanks.

 

[RonD]

No, analog gauges usually have a spring or bi-metal lever to provide stability to needle movement, no voltage required after shutting off

If gauge goes to 0 with key off it uses a spring(like speedometer), if it just goes down a bit but not to 0 then its bi-metal(like fuel gauge)

A Bi-metal piece changes its shape as it heats up and cools down, Turn signal Flasher uses bi-metal, Fan Clutch as well, and most fuel gauges use bi-metal