Parasitic Draw

[Ralls]

Hey there,
I have a 97 explorer 5.0 limited edition. I have an electrical problem I'm trying to narrow down. Starting about 2 weeks ago, the battery has been going completely dead over night. The battery was replaced late 2008 and the alternator was replaced (wasn't charging) a couple months ago.

I performed a parasitic draw test and I was getting a 0.56amp draw with everything off. I started pulling fuses and found out the JBL audio circuit was drawing 0.1amps (30amp mini fuse in the power distribution box under hood). My stock JBL subwoofer hasn't worked in about a year so something could be going on there. I was pulling more fuses and found the remaining 0.4amp draw was coming from fuse 25 in instrument panel which powers speedometer and GEM system.

This is where I'm stuck. I don't know what GEM really is or what all it controls. All I know is that it controls various modules. I noticed with that fuse removed, my wipers, power windows, and dome lights don't work. I'm sure there are other things GEM controls if I kept trying stuff.
Any advice on how I can narrow down with component is drawing power? It would be a little easier if I knew all of what GEM controls.

 

[ghosttrain2]

The gem controls or moniters the following:
1. all door ajar switches
2.liftgate wiper/washer control
3.air ride control (if equipped)
4.front wiper/washer control
5.4x4 control
6.key in ignition chime
7.battery saver relay
8.rear window defrost control
9.interior light
10.diagnostic input for airbag, RAP module, and ABS
11.door handle switches
12.seat belt warning
13.vehicle speed input
14.headlight switch (for warning chime)
15.all power window functions
16.illuminated entry
17.RAP module (anti-theft)
18.turn stop and hazard lamps
19.moniters digital transmission range sensor (what gear the trans. is in)
20.associated warning indicaters in instrument cluster

This information is from a 1997 ford evtm book.Some model lines/trim levels could be different, as well as some production date breaks.
The gem module is located to the left of,and next to your radio. A scan tool should be able to retrieve codes if any are stored.
Good Luck!

 

[Ralls]

That is exactly the kind of info I was hoping for. Thank you very much. It's fully loaded so I'm pretty sure I have all those options.

I disconnected a connector to the subwoofer AMP in the rear and that stopped my 0.1amp draw on that circuit. I think the amp is toast because I tried diagnosing it a long time ago.

I'll hunt down each of those components on the GEM system and hopefully find the problem.

 

[Ralls]

I just finished looking over everything and couldn't for the life of me figure out the problem. I went over every GEM part to make sure it worked and wasn't stuck on anything.
1. all door ajar switchesAll the doors turn on the dome lights when open and turn back off when closed
2.liftgate wiper/washer control works
3.air ride control (if equipped) works
4.front wiper/washer control works
5.4x4 control works if referring to the "normal road" and "off road" switch
6.key in ignition chime works
7.battery saver relay don't know where this is??
8.rear window defrost control works and doesn't stay on when switched off
9.interior light every light is turned off when locked down. such as dome lights, glove compartment, mirror visor lights, lights on doors
10.diagnostic input for airbag, RAP module, and ABS these components work
11.door handle switches pretty much same as #1
12.seat belt warning works properly
13.vehicle speed input speedo works
14.headlight switch (for warning chime) works
15.all power window functions all window switches work
16.illuminated entry work
17.RAP module (anti-theft) works
18.turn stop and hazard lamps works
19.moniters digital transmission range sensor (what gear the trans. is in) assume works because no shifting issues
20.associated warning indicaters in instrument cluster none stay on besides THEFT

I did find out that there is a 0.1amp draw total when I UNLOCK the doors and wait for everything to go to sleep mode. However, once I LOCK the doors and activate anti-theft, I get a 0.3amp draw total. So maybe the security is drawing too much? But even the 0.1amp draw is way higher than spec.
And to alliterate, the draw has to be on this circuit because with that fuse removed I get like a 0.005 amp draw.

 

[ghosttrain2]

Is this a true 12 volt draw? I disconnect the negative cable, wait approx 2 minutes, then place a test light between the neg cable and the neg battery post. If it lights up brightly-you have a draw .If it does not light up, no draw detected at the time it is being tested.
Another source for a draw can still be the alternater.
I have never used a ammeter to check a draw-only a test light. All the modules computers and the radio memory will draw something, but won't light a test light.
Hope this is helpful

 

[budwich]

you did alot of good "observation work".... I assume that you checked those circuits with your key off.... as you are looking for things that "maybe" operational then. After that, you need to try unplug circuits where possible to reduce circuit wire "mileage" and components. The draw may also come from the gem itself as it does switch (and "detect") things so you may have an issue there.

 

[Ralls]

Yes ghosttrain2, it is a 12v draw.
It lights up my test light and the DVOM shows 11volts.

All my tests are with everything off. All doors shut or I manually latched the hinges like the hood.

Yeh unplugging components one at a time would be the next step. I have no clue where the connectors are for most of them. The whole car would probably be apart! Where is the GEM located?

 

[budwich]

....
All my tests are with everything off. All doors shut or I manually latched the hinges like the hood.

....

I am not sure then about the things that you say "work"... as a lot of those functions are not suppose to work with the key OFF?????? IF they do, you have a stuck relay.

 

[Ralls]

I am not sure then about the things that you say "work"... as a lot of those functions are not suppose to work with the key OFF?????? IF they do, you have a stuck relay.

Sorry I didn't word that right. I checked to see if everything worked normally with the key on. Then I did my test with the ammeter with everything off.

 

[Ralls]

I can operate all the windows, sunroof, and lights with everything locked down and security on. Is that normal on these vehicles or is something stuck on? Doesn't seem like a good idea for anti-theft.

 

[budwich]

OK... we need to back track a bit as we are about to spin "out of control". Your problem is that you have a "draw" when the key is OFF and it kills your battery. Next thing we need to know is how long have you owned the truck and do you know about the various features (owner's manuals are handy). BUT in the short run, there are features that allow things to operate with the key OFF (after being ON) "for a little while" usually UNTIL a door is opened. Its called "accessory delay". There are others feature for theft etc... I don't know them all (don't have many on my truck). You need to do your testing after a "while" (and door open / closed) to ensure things have "died down officially".... in essence, only key ON ONCE (since you know the status of things from the first list), after that leave the key OFF and start checking things (assuming that you have recharged your battery).

 

[Ralls]

OK... we need to back track a bit as we are about to spin "out of control". Your problem is that you have a "draw" when the key is OFF and it kills your battery. Next thing we need to know is how long have you owned the truck and do you know about the various features (owner's manuals are handy). BUT in the short run, there are features that allow things to operate with the key OFF (after being ON) "for a little while" usually UNTIL a door is opened. Its called "accessory delay". There are others feature for theft etc... I don't know them all (don't have many on my truck). You need to do your testing after a "while" (and door open / closed) to ensure things have "died down officially".... in essence, only key ON ONCE (since you know the status of things from the first list), after that leave the key OFF and start checking things (assuming that you have recharged your battery).

I've been doing that all along. I'm well aware of modules going to sleep mode. It's about a 1.9amp draw with everything awake, then about 10 seconds later after locked down it goes down to 0.3-0.4amps. Then I can pull that fuse and make it nearly zero parasitic draw. I guess the next best thing to do is start taking off door panels and trim so I can disconnect components until the draw vanishes... not fun.

 

[budwich]

Okay... IF that's the case (you are aware), then IF your windows are working with your KEY OFF and doors open, you have a battery saver or accessory delay relay issue cause the windows don't work in that mode.

 

[Tbars4]

...Here are a couple good reads on the subject...
http://www.explorerforum.com/forums/showpost.php?p=2081752&postcount=3

http://www.explorerforum.com/forums/showthread.php?t=224016&highlight=severe+drain

 

[Ralls]

Thanks for those links. I do all my parasitic draw tests they way he described. What the guy did in that second link isn't a bad idea (keeping the circuit off until KEY ON using a relay). The only bad thing about that is the alarm system won't be on and you can't use any dome lights until you turn the key on.

I'm actually selling the truck. So I'm hoping to fix this as cheap as possible.

Okay... IF that's the case (you are aware), then IF your windows are working with your KEY OFF and doors open, you have a battery saver or accessory delay relay issue cause the windows don't work in that mode.

Forget what I said. The windows DON'T work with the security on. I didn't open&close the door before I locked it so the delay relay was still on allowing me to use the windows. I cannot use the windows with door open and key OFF as normal.

 

[Tbars4]

...I believe it was mentioned in the threads but, you have a GEM module and a lights out module (LOM) that take about 45 mins before they quit drawing power after the vehicle is shut off...The GEM I believe still draws some power though after wards..:scratch:

 

[Ralls]

The truck sat for two days and it started right up. Seems to be fixed.

 

[Tbars4]

...Do you know what the fix was for future readers???..:scratch:

 

[Ralls]

I don't really have a good answer. The only thing I changed was getting rid of the 0.100amp draw by unplugging the subwoofer amp.
I still had a 0.3amp draw from the GEM but like you said, its suppose to turn off after 45 minutes. I never waited that long to see if the draw went away. I'm going to try and not start it for a week and see what happens.