amp draw, GEM?????please help

pimpstang18 · Nov 25, 2005

i've got a 2003 gt and recently the battery has been dying. it's an optima red top. anyway i had the bat and charging system checked by ford and they are fine, they didn't have time to do a draw check so i did it myself tonight and found that fuse 39 which is only labeled as GEM (its a 5A fuse) is causing a draw of between 1.9 and 2.4 amps when the car is off. does anyone know what this fuse controls? or what GEM stands for? any help would be greatly appreciated because i have to drive back home tommorow and do not really have time to take it to the dealership so i'd like to fix this myself if possible. thanks.

triggz · Nov 25, 2005

pimpstang18 said:
i've got a 2003 gt and recently the battery has been dying. it's an optima red top. anyway i had the bat and charging system checked by ford and they are fine, they didn't have time to do a draw check so i did it myself tonight and found that fuse 39 which is only labeled as GEM (its a 5A fuse) is causing a draw of between 1.9 and 2.4 amps when the car is off. does anyone know what this fuse controls? or what GEM stands for? any help would be greatly appreciated because i have to drive back home tommorow and do not really have time to take it to the dealership so i'd like to fix this myself if possible. thanks.

"The GEM (Generic Electronic Module) module controls the windows, exterior lights, interior lights, sunroof, heated mirrors, rear window defogger, just about anything that pulls current that you control from inside the car."

All i can tell you is i had a problem where my gauges would full-sweep every time i started the car, and took about 30 seconds before they would actually even do that after starting the car..

i went pulling fuses and found that one was blown..

sho taurus:

ultrashock2112 · Nov 25, 2005

pimpstang18 said:
i've got a 2003 gt and recently the battery has been dying. it's an optima red top. anyway i had the bat and charging system checked by ford and they are fine, they didn't have time to do a draw check so i did it myself tonight and found that fuse 39 which is only labeled as GEM (its a 5A fuse) is causing a draw of between 1.9 and 2.4 amps when the car is off. does anyone know what this fuse controls? or what GEM stands for? any help would be greatly appreciated because i have to drive back home tommorow and do not really have time to take it to the dealership so i'd like to fix this myself if possible. thanks.

All I know is the GEM is the "Generic Electronic Module" and it controls the lights, locks, windows, everything electronic in the car that isn't directly engine related. The GEM module is usually on the driver side kick panel and has wiring harnesses plugged into it. If you have a load on the GEM module while the car is off, you should first probably look for anything obvious like an interior light that is on... Otherwise, I'd check the switches for the windows, mirrors, locks, one might be stuck down or something.

DropTopPony · Nov 26, 2005

GEM = truely outrageous

85 Coupe 5.0 · Nov 26, 2005

Did you wait 45 mins or greater before you observed your draw measurements? The GEM has to have time to 'go to sleep'. This 'time out' process takes 45 mins minimum. If at any time you open the door, turn on the ignition, open the hood, trunk ect. the timer resets. you must hook up your amp meter, wait 45 mins then observe the readings.

I have seen this at work several times, the customer performed their own amp draw test, started pulling fuses and proceeded to tell me that the GEM was causing a draw but couldn't figure out why. hook up the amp meter, wait, start pulling fuses, found a faulty alternator regualtor sticking on and draining the battery.

ultrashock2112 · Nov 26, 2005

85 Coupe 5.0 said:
Did you wait 45 mins or greater before you observed your draw measurements? The GEM has to have time to 'go to sleep'. This 'time out' process takes 45 mins minimum. If at any time you open the door, turn on the ignition, open the hood, trunk ect. the timer resets. you must hook up your amp meter, wait 45 mins then observe the readings.

I have seen this at work several times, the customer performed their own amp draw test, started pulling fuses and proceeded to tell me that the GEM was causing a draw but couldn't figure out why. hook up the amp meter, wait, start pulling fuses, found a faulty alternator regualtor sticking on and draining the battery.

Good point about the standby mode after 45 minutes... I still think it odd that there would be up to 2.5A going to the GEM if everything is off though.

85 Coupe 5.0 · Nov 26, 2005

ultrashock2112 said:
Good point about the standby mode after 45 minutes... I still think it odd that there would be up to 2.5A going to the GEM if everything is off though.

2.5A seems a little on the high side, surely he didn't have the door open while pulling fuses so that the dome lamp was on.

pimpstang18 · Dec 26, 2005

well i let it set for about a hour but i didn't know you had to let it reset again every time you opened the door, i'll have to go check again....i did however replace the dome light that looked to be singed on the connectors and the draw went down to .153 which i thought was acceptable but after letting my car sit for the weekend i went to start it and the batt was completly dead. i actually just posted another thread about that cuz i forgot about this one, see "gt draw please help"

thanks for the help though, now i know what to check for. as far as i can tell none of those items are still one when the car is off, guess i need to start unplugging stuff and testing it one at a time. thanx

sorry it took so long before i read this, i've been away at school and haven't had time to mess with it until this week, i just pulled the fuse and delt with no dome light, power lock etc. but that's getting old...

85 Coupe 5.0 · Dec 26, 2005

yea, got to leave the door alone, otherwise every time you disturb it it's another 30 or so min wait. a trick to that one is, open the door, then take a screwdriver and use it to latch the door latch, that way you can leave the door open and pull fuses, just DO NOT forget to un-latch it before you slam the door, otherwise you could damage the latch.

by the way, the spec is 50 milliamps, or 0.050A. any more than that and after about a day or so you got a dead battery.

MadDog2020 · Dec 26, 2005

Funny, my 00GT draws about ~130-140 mAmps as well. The car doesn't go much longer than 2 or 3 days tops without being driven and it starts OK. Would be curious to see if an idle 7 days kills it.

I pulled every fuse imaginable and my GEM is causing all the current draw, even after waiting the 45 min and what nots. I still wonder about the sticking voltage regulator though. Do you have an aftermarket chip in place? I have a Diablo Chipmaster Revolution, wondering if it is causing something?

Sorry to but in about my problem, just putting this out there so you know you are not alone... Good luck, keep us posted of your findings!

damacman · Dec 27, 2005

subscribing

85 Coupe 5.0 · Dec 27, 2005

MadDog2020 said:
Funny, my 00GT draws about ~130-140 mAmps as well. The car doesn't go much longer than 2 or 3 days tops without being driven and it starts OK. Would be curious to see if an idle 7 days kills it.

I pulled every fuse imaginable and my GEM is causing all the current draw, even after waiting the 45 min and what nots. I still wonder about the sticking voltage regulator though. Do you have an aftermarket chip in place? I have a Diablo Chipmaster Revolution, wondering if it is causing something?

Sorry to but in about my problem, just putting this out there so you know you are not alone... Good luck, keep us posted of your findings!

I kinda over-exaggerated the draw, however, Ford spec is 50 milliamps. so if you were pulling that 50 milliamps it would probalby take more towards a month or so. with your 130 to 140, i'm guessing around 2 weeks or such, merely because i'm too lazy to look up what reserve capacity you should have minimum and divide out how long your battery can sustain that draw before discharging.

c'mon guys, get those doors open, latch the latch and setup your ampmeter for draw testing, wait 45 mins and start pulling fuses.

if it's the GEM, start un-hooking every output that the GEM controls, dome lights, ect. but don't disturb or unhook an input otherwise you'll wake up the module and chase your tail or replace a $300.00 GEM and still have the same prob.

If you get all the outputs un-hooked and still have a draw, it very well could be the GEM, although it's not something seen on a regular basis, it's usually an alt regulator or something like a cell phone kit plugged into the cig lighter, see that happen a lot, old people also love those car ionic breeze machines.........

D'SDOUBLEOGT · Dec 27, 2005

I am having the same (exact) problem. I have the same battery and the same amount of draw. I hope this helps you… There is a box located just above the fuse box and to the outside of the car that I think is the GEM or at least that is what everyone is saying on here. Anyways I disconnected the black connecter on the forward most part and the draw goes away. When the connecter is connected the box clicks like a relay does and of course the draw comes back. My question is what (exactly) do I have to unplug as far as window motor or rear defroster or is there a way to get a wiring diagram for this specific car. I know for me at least a diagram would work and could help the others with the same problem.

pimpstang18 · Jan 1, 2006

well my car seems to be fine at the .153, i put a new optima in it and even after a few days sitting in the garage it starts up strong

could a radar detector plugged into my cig lighter be a problem even if it's turned off when my car is off? i did unplug it when i tested the draw although it was plugged in the first time because i forgot about it and it started rapidly clicking when i hooked up my meter.

pimpstang18 · Jan 1, 2006

MadDog2020 said:
Funny, my 00GT draws about ~130-140 mAmps as well. The car doesn't go much longer than 2 or 3 days tops without being driven and it starts OK. Would be curious to see if an idle 7 days kills it.

I pulled every fuse imaginable and my GEM is causing all the current draw, even after waiting the 45 min and what nots. I still wonder about the sticking voltage regulator though. Do you have an aftermarket chip in place? I have a Diablo Chipmaster Revolution, wondering if it is causing something?

Sorry to but in about my problem, just putting this out there so you know you are not alone... Good luck, keep us posted of your findings!

i have the diablo predator but i installed the aftermartket tune months ago and it ran great up until recently so i doubt that it has anything to do with my problem

Phibernaut · Jan 14, 2006

LOL

LOL - "Gem = truly outrageous"

funny sh**

z28forlife · Mar 4, 2013

Old thread revived. I hooked up my multimeter and got 1.2 amp draw for around 30 seconds then it would drop to .250mA. I did this both with the alternator hooked up and unplugged. When I would pull #39 fuse the draw would drop to .004 draw. Right where it should be. I had the door open but the dome light removed. I pulled every other fuse under the dash and non of them stopped the draw except #39. I did pull a maxi fuse 40amp fuse under the hood but that took the draw to 0.000. Please help!

scotty113x · Jan 5, 2023

I'm having basicly the exact same problem. And same fuses are the problem. I know #39 is the GEM. Any updated insight/fixes would be greatly appreciated. Also does anybody have a full and accurate list of what the GEM controls?

amp draw, GEM?????please help

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