Yet another mystery parasitic drain thread

[SaltCoveredFord]

'99 Eddie Bauer Explorer - Factory Mach Audio Stereo (CD/Tape/6-disc/subwoofer in back)

Been dealing with a major power drain over the past few weeks. To the point I'd have to pull the 60A fuse under the hood (that powers my interior fuse panel) whenever I parked if I wanted to be able to start it later. I've read almost every thread on this forum dealing with battery drains - with no luck yet (though doing the accelerator mod a few nights ago made me smile).

Current tests results (Neg Post to Neg Cable after truck has been sitting for 1+hour):

With all fuses installed - the ampmeter reads "OF" (ampmeter can't read it - only up to 200mA)
With all fuses installed except the two below - the ampmeter jumps from 9mA -> 14mA -> 9mA every 5 seconds (which is well within the normal range from what I've read)

The two suspect fuses:

#25 - 7.5A Generic Electronic Module (GEM), Instrument Cluster, Securi-Lock
#29 - 25A Radio (though the manual says it should be 10A - maybe because of the stock CD-changer & subwoofer)

If EITHER of these fuses are installed, the ampmeter goes off the charts.

• I've disabled (disconnected power to) the rear amp just in case there was an issue with the amp/subwoofer - that did nothing.
• I've pulled the stereo - no visible loose/damaged wires at the back of the stereo - haven't dug much further than that.
• I've also tried disconnecting the radio entirely to see if there is any kind of drain difference with the two fuses - no change.

I'm still looking for a wiring diagram. The Haynes manual I picked up the other night doesn't go past 1995 for non-engine wiring diagrams. If anyone can point me to a good diagram that would be great.

Do any of the components on #25 (including items hooked into the GEM) share anything with the radio (#29)? I've got to believe that the drains on the two fuses are related. Is there somewhere I can find a list of what exactly is hooked into the GEM? So far it's just been me coming across things that don't work when I have the fuse pulled ("Oh, I guess I can't roll down my window").

Any help would be greatly appreciated.

-Salty

 

[jremington59]

Number 25 is going to read off the hook until the vehicle "goes to sleep" and goes into energy saving mode.

In your power distribution box under the hood, you will find a 25 amp mini fuse that is for your alternator/voltage regulator. Pull that fuse and check and see if your draw drops. I had a problem that I couldn't find and it ended up being a short in my voltage regulator. It would kill a brand new fully charged battery in less than a day....

 

[budwich]

It appears that you have "narrowed" down your search by pulling fuses... good. Now that "type" of testing is done, you need to go the "other way" ... pulling plugs. The GEM is a "good candidate" to pull... as it is likely a "route" for things. Pull it and see what happens to your draw. You can go from there. I guess the other question is "are there any strange things happening... windows work, radio works with key off (doors have been opened), etc... those observations might help direct your attention.

 

[hworksinc]

Fuse 29 is for the entire audio system, and it should indeed be 25A. The powered components are the radio and subwoofer amp, as well as the rear control panel and the CD changer. I think this circuit should draw well under 100 mA when the vehicle is off.

NOTE: The CD changer and rear control panel are fed by fuse 34 (7.5A), but the power to fuse 34 comes from fuse 29. Try leaving fuse 29 installed, but remove fuse 34 to see if there is a problem with the CD changer or rear control panel.

Question: How did you disable power to the subwoofer amp during your testing? Did you actually remove the rear quarter panel trim and unplug the connector at the amp?

Fuse 25 powers the electronics for the gauges, several instrument cluster warning lights, the PATS module standby power, and the GEM. As jremington59 said, this circuit will pull a bit of power for a few minutes after the car is turned off. Once the GEM goes to "sleep" the draw on that circuit should drop under 100 mA.

Before doing further testing, I'd recommend testing your battery and getting an ammeter that reads higher than 200 mA. It should take a sizable power draw to drain the battery overnight (10 hours), between 5 and 10 amps depending on the battery. It sounds like you're experiencing a dead battery after just an hour or two, which would require an even larger drain. Even if there is something wrong in one of these circuits and you're getting a drain of 1-3 amps (for example), you battery should not be completely dead. Without a real current reading of the parasitic drain I can't predict if there's something wrong with your battery or not, so I'd recommend having your battery tested to rule that out.

In terms of finding your power drain, focus on the fuse 29 circuit first. You've already tried removing the radio and sub amp from the circuit. Next you should check the power draw on fuse 34 (remember to leave fuse 29 in), and then disconnect the CD player or the rear control panel to see if one of those is the problem.

 

[SaltCoveredFord]

Thanks for the great replies/info - I didn't have much time over the weekend to look into it further, but an update/replies:

Over the weekend I drove the truck around - removing I/P fuse 25 & 29 when I parked and putting them back in when I drove around (mainly because #25 controlled my wipers which I needed). Truck started every time - no hesitation or multiple tries needed.

jremmington - I'll try to pull that fuse and see if it makes a difference. I'll try pulling the alt/voltage regulator and see if that changes the draw. Before I test I always let the car sit for an hour or more, does the action of testing it (disconnecting the neg post/cable, checking with voltmeter) wake the fuse #25 components up? If so, what's the best way around that?

budwich - haven't noticed anything weird as of yet. I'm still looking for a good diagram or pictures of what the components look like. I've heard the GEM is behind the radio - but I pulled the radio out and saw a few boxes there and no idea which one to pull. Also, I need to read up on how to test at the other end (I don't want to probe something that's going to fry my car).

hworks - thanks for the stereo info. I figured the manual's spec didn't account for the amp/subwoofer, but I totally forgot about the rear control and CD changer. I haven't used my CD changer in ages, and my rear controls are constantly kicked by my 4-year old son in his car seat (might be a place to start). I'll leave 29 in and check 34 to see if it's a problem with the CD changer or the rear controls (I'll also confirm they're working properly). With the amp/sub, I pulled the rear quarter panel and unplugged the amp (I've opened it up before to replace the subwoofer).

I've tested the battery and altenator recently - both tested great. I had a better ampmeter, but I blew the fuse (I think I had it on the wrong setting and touched the post/neg battery terminals) - and noone I can find (including radio shack) has the right fuse. I'll look around for a better ampmeter.

Again thank you all for your replies, I'll let you know how the testing goes.


P.S. There any way to get email notification after each reply to this thread? I had it set to Instance Notification but only got one e-mail and didn't see hwork's post till this morning.

-Salty

 

[jremington59]

The GEM is on the left hand side of the radio. It's mounted with one small bolt. It's kind of shaped like a VCR tape.

 

[SaltCoveredFord]

Update:

Jremmington - I pulled the volt/alt fuse from the engine compartment fusebox - there was no difference in voltage. Thanks for the info on identifying the GEM - I'll look for it later when I dig in.

Hworks - You nailed it on the head. I pulled fuse #34 (with fuse #29 in)and it the multimeter read 13-14 mA. All of the functions of the rear controls & CD changer work correctly - so I'm going to have to dig around to determine the drain. I popped the radio out and disconnected the plug for the CD-changer & rear controls. Put fuse #34 back in and confirmed multimeter still read 13-14 mA.

Budwich - I'm going to have to find instructions on pulling the armrest/center console apart to find the issue with the changer/rear controls. Or it may be on the wires at the radio end (they visually looked ok). I'll look around for a bit to see what I can find - but I may end up back here.



Fuse #25 still reading off the charts - so I have a question. As for testing - Jremmington mentioned about the #25 components (GEM)reading off the chart until the car goes to sleep. Does me completing the circuit (connecting neg post to neg cable using my tester) wake it up? If so, is there a way to check fuse 25 in sleep mode (I always wait at least an hour after turning the car off to test)?

I'm wondering if I should take the chance that the Changer/Rear Controls were the only thing draining the battery and #25 is reading crazy just because the car is not yet in sleep mode? I can put all the fuses in (with the CD-changer & rear control still disconnected from the radio) and see if I need a jump in the next day or so?

Also planning on picking up a better multimeter.


-Salty

 

[hworksinc]

I think that disconnecting/reconnecting the GEM will "wake it up" so to speak. You could try a more delicate approach so that you don't actually disconnect the negative battery cable - loosen the clamp, hold one multimeter probe so that it touches the clamp (use the same hand to hold the negative clamp), and hold the other probe directly to the battery post, then carefully lift the clamp off the post, maintaining contact with both probes. I've used that technique in other applications, but it should work here as well.

 

[SaltCoveredFord]

Great advice, I'll try it tomorrow.

And I'm a bit more pressed to find the cause of the changer/rear contols now that I found the radio connection I pulled also controls the steering wheel controls.

 

[budwich]

Great advice, I'll try it tomorrow.

And I'm a bit more pressed to find the cause of the changer/rear contols now that I found the radio connection I pulled also controls the steering wheel controls.

not sure I follow this.... what is the "cause of the changer/ rear controls"?? what's happening. Further, what happens with your "drain" problem IF you just pull your battery saver relay.

 

[SaltCoveredFord]

Sorry, that post was from my phone - didn't really explain it well. After finding that the items on fuse 34 (CD changer, rear audio controls) were the issue (and not fuse 29) I thought I could survive with just pulling the plug on the back of the radio that went to those two components. However I found out that that plug also was for my steering wheel audio controls (which I use often). So I can't just ignore the issue.

I'm not sure where the battery saver relay is - my manual is in my truck. I left fuse 25 (GEM, PATS, gauges, etc) in overnight and the truck started up this morning fine - but I'm going to test fuse 25 using hworks method at lunchtime to see if there is any substantial drain.

If there's no large drain, then I'll be off to determine why the CD-changer or Rear controls are drawing power even when the truck is off.

-Salty

 

[budwich]

"If there's no large drain, then I'll be off to determine why the CD-changer or Rear controls are drawing power even when the truck is off.".... cause they can....

thanks for the clarification. Anyways, you are then probably going to need a pinout for the CD player and determine the "signal control" lead from the radio.... not sure about specifics but its probably either a "grounding" or something like that.... that "tells" the CD player that the radio section is either "only in use" OR that the truck is turned off.... and there for the CD player can "take a rest".... I make that "presumption" based on the fact that the fuse 34 is delivering "always hot" battery... thus if the CD player doesn't get its "shut down orders" from somewhere... it will always be on... maybe.

further to that with your "kick me butt" son ...:-0 I would go to the rear controls and pull the plug there ... it is possible that the "odd kick" might have knock the senses out of the controls.

 

[jremington59]

Go through step four in this post. But don't remove the two 8mm bolts, just the 10 mm. When you unplug the plug the power to the cd changer will be cut off. It takes about three minutes.

http://www.explorerforum.com/forums/showthread.php?t=209770

 

[SaltCoveredFord]

Thanks for the link Jremmington - reading it, however I'm wondering if the instructions might be the different for my truck since I have the message center in that console area. I'll take a look at lunch and see if it looks similar. Probably won't be able to dig far into it until tonight at earliest.

In the mean time I'm also going to:

• Check fuse 25 using the method hworks said to see if it's still pulling after the car is in sleep mode.
• See if I can still use the steering wheel audio controls if fuse #34 is pulled. If it works, I'll plug that third group of wires (changer/rear controls/steering wheel) back into the radio so I can use the steering wheel controls for now.
• Search around for a pinout for the radio like budwich said so I can know what I'm pulling and what wires I need to be looking for when I get into the console.

Thanks again for the help fellas. I've been stalking the site for a while and was able to find answers to alot of my problems just searching.

I've been wasting gas (and having fun) ever since I did the accelerator cable mod last week. I don't think the truck had seen WOT before - my wife was the previous owner and when I did the mod I had about an inch of slack in the cable (so I doubt I ever hit WOT). If I get this problem licked I may start getting into some other (inexpensive) mods.

-Salty

 

[jremington59]

Before you go any further, take a voltmeter and tll us what voltage you have at the terminals with the engine running.

There's a chance that something else could be giving you this drain before the vehicle goes into battery saver mode and you could simply have a weak alt.....

 

[SaltCoveredFord]

Jremmington that may have to wait as I think I did hworks method incorrectly and the fuse in my ampmeter just blew.

I was able to get into the console and disconnect the cd changer, but can't test it now.

I see the batch of wires to the rear audio controls, but the rear A/C controls are in there as well so I didn't mess with them.

I'll grab another ampmeter (or at least fuse) and let you know the results.

-Salty

 

[SaltCoveredFord]

First of all - I haven't tested the voltage yet, I have a new multimeter that has higher maxes (600 DC V max, 10A DC Current max) but when I tried to do a volt test on the battery (with the engine still off) I saw more sparks than I was comfortable with and quickly held off.

The mA current results have me puzzled.

So with the new multimeter (that reads higher than 200mA) I tested the following (not in sleep mode):

• Fuse 25 (GEM, etc) out, Fuse 34 & 29 in, CD changer still connected - Result = ~250mA draw
• Fuse 25 (GEM, etc) out, Fuse 34 & 29 in, CD changer unplugged at changer end - Result = 14mA draw
• All fuses in (including #25), CD changer unplugged at changer end - ~250mA draw (not in sleep mode)

Aha! So the CD Changer was the culprit in the fuse 29/34 fiasco! With my new ampmeter I was curious if the total drain would be ~500mA combined draw if the CD changer and Fuse #25 were in. So I tested:

• All Fuses in (including #25), CD Changer connected = ~250mA draw

Well, that's kind of weird. Let me try them individually again...

• All fuses in (including #25), CD changer unplugged at changer end - ~250mA draw
• Fuse 25 (GEM, etc) out, CD changer connected - Result = ~14mA draw

Wait, what???? I just did this same test the CD changer a few minutes ago and it was pulling 250mA! I test it multiple times with the same results. I turn on the radio to make sure I didn't leave the changer disconnected somewhere... it cycles through the CDs and plays just fine.

Could the plug that goes into my CD changer have gotten loose enough to keep the circuit open and the act of me plugging it back in caused it not to draw any power anymore?

I'm still scratching my head over the whole thing. I'm going to try to go out again in a few minutes after the truck is asleep and attempt to test fuse 25 and trick the car into thinking it's asleep. I have plenty of fuses just in case.

I usually enjoy solving problems, but I'm begginning to hate electrical work.

-Salty

 

[SaltCoveredFord]

I just tested the truck With fuse 25 in and I'm fairly certain what I did wouldn't take the truck out of sleep mode. It read about 250mA... That combined with the fact it hesitated on startup makes me think the car isn't sleeping. I had no issues starting it recently when I had #25 and #34/29 fuses out.

Until I can test further I'm going to have to pull #25 when I park.

-Salty

 

[SaltCoveredFord]

Well ever since I pulled #25 when parked the engine has started right up. I'm planning on trying to test 25 again in the supposed sleep mode. After that I'm going to see about disconnecting the gems and testing the drain (right away and also after 20 min).

Is there anything in the truck that would tell me if sleep mode is on (light/indicator/anything)?

-Salty

 

[jremington59]

Are you pulling the bulb out thats underneath the hood when you do this test?

I still wish you would check the voltage you're getting at the terminals with the engine running. If your alt is getting weak it will not be charging the battery fully, and a weak battery can go dead on it's own.