Parasitic draw, .455 amps, fuse #25 the problem???

[1996BLKBauer]

Hey guys, I finally got around to checking my '96 Eddie Bauer for the Parasitic draw it had, it would take about 2 days for it to die, and it would be completely dead, no lights, no door chimes, nothing. With everything hooked up, I had a draw of .455 amps, which varied a little bit, maybe by .002amps either way. After disabling all of my aftermarket things, such as the head unit, the amp, off road lights, usb charger, cb radio, I still had a draw of .455 amps, so that makes me happy that nothing that I have installed is killing that battery. So I then start the tedious task of pulling all of the fuses. I finally get to fuse number 25 on the interior fuse panel, which is labeled Speedometer, and GEM system, and the amp draw drops to .131amps, which is well within the specified range it should be. I know that my GEM module is having some issues, the Auto lights stopped working almost 4 years ago. So is it a common issue for our GEM modules to start having a Parasitic draw? It would make sense, the module appears to do a lot of things, and the truck is now getting pretty old.

Any input would be greatly appreciated guys!

The truck is:

1996 Eddie Bauer Explorer, V8, AWD, Auto Hvac, basiclaly fully loaded without the cellular phone option.

 

[1996BLKBauer]

A little bit of an update. I got to the GEM module, if I unplug the C283 plug from the bottom of the GEM the draw drops to .131amps, this plug has the power and grounds, so this leads me to believe that the issue is either within the GEM module, or in some system it controls. There are 3 other plugs on the side of the module C280, C281, and C282, when I unplug both C281, and C282, the draw stays at .455amps, but when I unplug C280 it then drops to .131amps. So I then proceeded to individually pull pins out of the plug one at a time, and re plug it in, this took some time with there being 26 pins in this particular connector. Unfortunately I was never able to get the the draw to drop to .131amps again, so at this point I am pretty much thinking that the issue is ONLY the GEM module. I am actually quite surprised that I never saw it drop at all, but I am not about to spend another hour pulling pins just for the same outcome. So I am 99% sure all I need is a gem module, unless anybody else has any input?

 

[J_C]

Yes it seems like it's probably the GEM, and it is odd that pulling the whole connector C280 drops the current but no individual pins do.

Is the GEM getting hot? Might take a good 10 minutes or more to notice heat buildup, but If it's the source of a short circuit, at near half an amp that's 6W dissipated as heat "somewhere". Then again if it's 90 degrees in the shade outside, might not be as easy to detect heat buildup as on a cool day or night.

Don't know if I'd be 99% certain it's the GEM though, probably but with it being more expensive than anything else I would poke around a bit more, try to get the pinout for the C280 connector and if if there are any unusual voltage or current readings on any particular pin, not that it necessarily proves anything as I just get a headache trying to look at what Ford calls diagrams instead of releasing proper electronic schematics, but anyway I'd look at the pinout and pull some fuses related to those circuits.

Did you keep pulling fuses when you found that pulling the GEM fuse dropped the current, or stop there? If you stopped, I would proceed to pull the rest of the fuses while leaving the GEM fuse plugged in. Here is C280 pinout as posted in the following topic by 2000StreetRod: http://www.explorerforum.com/forums/index.php?threads/97-explorer-gem-diagram.270218/#post-2395475

C280:
1, dk blu/org, defrost switch in
2, wht/ppl, ctm diagnostic in
3, ppl/lt grn, door handle switch in
4, wht/ppl, lift gate in
5, lt grn/yel, LR door ajar in
6, pnk/lt blu, RR door ajar in
7, gry/red, RF door ajar
8, yel/blk, LF door ajar
9, blk/org, door ajar ind cntl
10, blk/pnk, key in ign sw
11, wht/blk, park/headlamps on in
12, yel, fasten belt ind crtl
13, lt blu/org, interval/delay wash in
14, blk/wht, gnd
15, blk, park sense
16, pnk/lt grn, door unlock relay cntrl
17, dk grn/ppl, door disarm in
18, gry/lt blu, wiper speed crtl
19, yel/wht, brake/run relay crtl
20, tan/yel, sound tone in
21, gry/red, signal return
22, pnk/yel, wiper mode select sw
23, brn/lt blu, seat belt warn sw in
24, tan/red, wsher pump crtl
25, lt blu/wht, diagnostic in
26, blk/wht, gnd

I wonder if you could negotiate some kind of money-back-if-it-doesn't-work GEM purchase at a junkyard. Since the vehicle runs that'll get you there to check it before leaving.

 

[J_C]

Here's another useful post by 2000StreetRod with all 4, 3 C28(n) pinouts, but for a '97 which I can only assume is the same as I thought it changed in '98:
http://www.explorerforum.com/forums...iring-diagram-for-a-1997.425670/#post-3410232

 

[1996BLKBauer]

Thanks for the input, and all the links. I did continue pulling fuses after I got to fuse #25, the only other one that changed the amp draw at all was fuse #27, but it only dropped it down to .308 amps, I forgot what exactly it said that fuse powers, but I do remember it was a lot of things. I did however pull #25 fuse, and the amp draw dropped to .131amps, after that I pulled the #27 fuse the amp draw did not change, so that leads me to believe that somehow it is part of the GEM system, or a component that it controls, which was already powered down when I pulled fuse #25.

Pictures for reference:
C280 connector, the top one when the GEM is installed in the vehicle.

And C283, the connector on the bottom of the GEM module.

Since I ran out of time for today, and really for the whole rest of the week, I just installed a switch inline with the fuse, and when I park the truck, I just turn off the GEM module, I'll probably pick this back up next weekend. if anybody wants to chime in with their story, please do, I am interested in hearing about it.

***ALSO, I did take apart the module, and inspect for any hot spots, crack solder joints, ect. I came up with nothing...

 

[imp]

0.131 Amps. is still too high, I think. Where did you obtain that number as normal? PCM keep alive current is generally about 0.005 Amps (5 Milliamps), and that alone will drain a full Group 65 battery down in two or three months. 0.131 Amp. should do the job 26 times faster, or about 2 to 3 days. It seems an average car battery has a capacity of about 40 Ampere-Hours, so it could deliver 0.131 Amp. for about 305 hours, that would be 12 days.

Surely, a car standing 12 days will not experience a dead battery, will it? I'm using kind of a$$-pulled numbers here, but 0.131 just sounds way high. imp

 

[1996BLKBauer]

0.131 Amps. is still too high, I think. Where did you obtain that number as normal? PCM keep alive current is generally about 0.005 Amps (5 Milliamps), and that alone will drain a full Group 65 battery down in two or three months. 0.131 Amp. should do the job 26 times faster, or about 2 to 3 days. It seems an average car battery has a capacity of about 40 Ampere-Hours, so it could deliver 0.131 Amp. for about 305 hours, that would be 12 days.

Surely, a car standing 12 days will not experience a dead battery, will it? I'm using kind of a$$-pulled numbers here, but 0.131 just sounds way high. imp

I honestly have no idea what Ford suggests for an amp draw, but I work at a GM dealer, and GM's rule of thumb is anything up to .250amps is acceptable. This is on any GM vehicle, even with lower rated batteries. I figured it was actually really good with 0.131 amps. Plus my truck rarely sits for any longer then 4-5 days without being started. It may be too high for say a classic car that sits for months on end, but not for a vehicle that get driven almost every day.

 

[imp]

I honestly have no idea what Ford suggests for an amp draw, but I work at a GM dealer, and GM's rule of thumb is anything up to .250amps is acceptable. This is on any GM vehicle, even with lower rated batteries. I figured it was actually really good with 0.131 amps. Plus my truck rarely sits for any longer then 4-5 days without being started. It may be too high for say a classic car that sits for months on end, but not for a vehicle that get driven almost every day.

A hefty parasitic draw would be detectable by leaving the vehicle sit 4 or 5 days, starting with full-charge, and measure charge remaining after that length of time. Cycling a battery is what kills it sooner. A car which must always crank a long time before starting, for example, will always get a shorter battery life. I guess all the new-fangled stuff that needs memory kept up, is a necessary part of life today. The old classics had NO parasitic draw, no computer, but I gotta say, my Explorer starts so fast it hardly spins a turn or two, and I just bought a new battery on general principles, old one was 5 years.

Here's something which just popped into my head. Air bag power supplies or modules, have a big capacitor in them, with a bleeder resistor across it, so I think the more air bags (some have NINE??) the higher the parasitic draw, if designed to deploy bags even if vehicle is standing and shut down. There seems to be quite the debate over that issue. If a guy is parked, sitting in his car, should air bag protection be still there, to cover some maniac plowing into him? imp

 

[J_C]

I just measured mine, the '98 XLT SOHC. Hadn't ran it since Friday, did not start it, just opened door for a couple seconds to pop the hood. There is no hood light.

235mA, higher than I expected it to be though I know of no other problems with it, besides that being higher than I'd like. If it were a daily driver I might start investigating it more but for now I'm leaving it be, doubt it's the alternator as I just swapped in a new one less than 1K miles ago.

Anyway I'd expect a '96 without PATS to at least read less than 235mA. Eventually I may look into mine more and if I don't find any faults, since I don't drive it regularly these days, I might look into throwing a solar panel on top to slow the battery discharge since it is now always parked outside.

 

[Turdle]

Food for thought. The battery saver is part of the GEM, according to this thread

http://www.explorerforum.com/forums/index.php?threads/battery-saver-relay-problem.220415/

edit. Read post 13.

 

[1996BLKBauer]

Food for thought. The battery saver is part of the GEM, according to this thread

http://www.explorerforum.com/forums/index.php?threads/battery-saver-relay-problem.220415/

edit. Read post 13.

hmmmm, Ill have to check this out. I never even knew that relay was there. Ill have to check it out before I head to the junk yard this weekend. $5 would be a lot better then $50 for a used GEM. although I may just get a gem anyway, like I said I lost the auto lights about 4 years ago, and when I diagnosed it then, it had something to do with the GEM.

 

[bobflood]

I got a GEM thru eBay for $20 - fixed a lot of weird issues. When you open door, even briefly, you "wake up" vehicle and current draw will increase - usually for 20-30 minutes. True parasitic draw has to be measured after it goes back to "sleep." According to the textbook in the automotive courses I am taking, max parasitic draw should be .050 amps (50mA). Good luck.

 

[imp]

I got a GEM thru eBay for $20 - fixed a lot of weird issues. When you open door, even briefly, you "wake up" vehicle and current draw will increase - usually for 20-30 minutes. True parasitic draw has to be measured after it goes back to "sleep." According to the textbook in the automotive courses I am taking, max parasitic draw should be .050 amps (50mA). Good luck.

@bobflood You make an excellent point! I never thought of the fact that preparing to use the vehicle (opening a door) would surely set the stage for electronics working, and only the battery can supply the juice until the engine starts. I believe in my 2004 Ex, it's 10 minutes, as anything left ON shuts off after that length of time.

Agree 50mA is a good MAX number. The guys talking 5 to 10 times that, are looking at a battery dead after being parasitized for a week or so. Good luck in your course-work! I had hoped to teach Electric Theory here in Mohave County (AZ), but DeVry Technical Institute could not produce a transcript of my degree there, I'm that old!! imp

 

[1996BLKBauer]

I got a GEM thru eBay for $20 - fixed a lot of weird issues. When you open door, even briefly, you "wake up" vehicle and current draw will increase - usually for 20-30 minutes. True parasitic draw has to be measured after it goes back to "sleep." According to the textbook in the automotive courses I am taking, max parasitic draw should be .050 amps (50mA). Good luck.

When testing I had the door latched closed, and I let the vehicle sit for a bit, probably about 15 minutes, before I started testing. While at work this week we where slow, so I tried something on two vehicles, one was a 2012 Buick Enclave, and another was a 2014 GMC Acadia. the Batteries are both rated for 800CCA. I did the same Parasitic draw test that I did on my truck, and I even let the vehicles sit for at least 20 minutes, as I did other jobs. after about 30 minutes the Buick was sitting at .189 Amps, and the GMC was sitting at .186 Amps... Regardless of the vehicle its self, I have a battery that is rated higher, and a draw that is lower, so that's why I feel like my draw is totally fine. .050 amps is also what my Electrical book(about a 3 year old book) said was good for a parasitic draw, I feel like that is something that needs to be updated in the books, most vehicles on the road now have something like 30 modules, that need keep alive memory, so they all draw some sort of power.


Also I checked out the Relay situation.
It would appear that the relay is not the cause, even though with the truck off for 15 minutes it did indeed get warm, and when I removed it the draw go away, but when it was replaced with a known good relay, I had the same draw again, I feel like this is more a effect, and not the cause of the draw. I am still leaning on the GEM, and I'm just going to get one at this point, I can grab one for $20 at my local junk yard, so I'm not worried about it.

Just in case anybody else wants to see if their relay is causing an issue. I have some pictures for you.

Picture of the location of the relay box. Known as the "Relay Module"

And what Relays are in there, this diagram is weird, and it shows the pins, not the individual relays them self's.

I'll report back sometime this weekend to let everybody know how things turned out.

 

[1996BLKBauer]

Well, no luck at the Junk yard. I literally took apart 20+ Explorer dashes, just to find that none of them had the right GEM for my truck. I was surprised to see that many '96-'97.5 Explorers there, but none of them where right, if it was an Eddie Bauer, it was not loaded, and most where just XLS, or XLT. So if anybody has a spare, GEM or truck with a GEM, I'm looking for Ford part number
F67B-14B205-BA, which apparently is only for a '96, through early 97 trucks.

 

[imp]

@1996BLKBauer Please describe in detail if you will, the method you are using to measure the parasitic draw, and what sort of instrument you are using. Thanks! imp

 

[1996BLKBauer]

Disconnect negative battery terminal, jump the cable to the battery with an 8 gauge wire, put my snap on(don't know the model number, but it cost me a lot, lol) meter inline, set to amps. With the plugs in the correct spots. Disconnect the 8 gauge wire (this wire is basically to prevent a huge spike in amps when I first connect the battery back to the vehicle). Now the meter is the only path for the negative battery terminal to the battery it's self. Before pulling the fuses I usually wait about 15-20 minutes, this is with any car. Then I proceed to pull fuses. If any doors need to be open I set the latch with my hands, or a screw driver. Then start the tedious task of pulling the fuse, waiting a few seconds, and watching the meter. That is basically how I have done every draw test, it hasn't failed me yet. I feel like this is the correct method, but I am always up for some better input. Heck, if I don't need to buy a GEM, and I need to retest something else, I am down for that as well. but I feel like there is no other option at the moment.

 

[imp]

@1996BLKBauer Thanks much! What I was after was, some clamp-on devices claim to be able to measure D.C. current. Unless Electric Theory has changed drastically since I studied it, a non-varying D.C. current produces no changing magnetic field about a conductor, and therefore no means of inducing a current in a measuring device. Maybe they work by lining up a compass needle!

 

[1996BLKBauer]

@1996BLKBauer Thanks much! What I was after was, some clamp-on devices claim to be able to measure D.C. current. Unless Electric Theory has changed drastically since I studied it, a non-varying D.C. current produces no changing magnetic field about a conductor, and therefore no means of inducing a current in a measuring device. Maybe they work by lining up a compass needle!

I totally understand, I have yet to use an Amp Clamp, one because I don't have one, and secondly, because I have had no need to get one. At work we have a VAT-40 for testing alternators, That works surprisingly well. For anything that I currently deal with the 10amp max from my meter works just fine.

 

[bobflood]

@bobflood
Good luck in your course-work! I had hoped to teach Electric Theory here in Mohave County (AZ), but DeVry Technical Institute could not produce a transcript of my degree there, I'm that old!! imp

Imp - I'm that old too. I had to get transcripts for my Georgia Tech EE degree for the tech school admissions. My first two years were "pre computer" and were so illegible that the school wouldn't take them! So even though I have a BEE, an MBA, and 45+ years work experience, they still made me take tests to prove I could do tech school work! Got to love bureaucracy! In the end, it was easier to take the damn tests than fight with them.