Parasitic Current Draw??

[dtf99]

Hi,
I appreciate the opportunity to make my first post here.
I just got back into town after being away for 8 weeks. My 2004 Explorer, which was parked in a fairly warm garage, had a dead battery.
After charging the 1-year old battery, I measured a 0.7 amp current drain using a Fluke clamp on dc ammeter. In the 56 days I was gone that would certainly have drained the battery.

I removed fuses in the Power Distribution Box until I found the offending circuit. It was the "Memory (PCM/DEATC/Cluster) Courtesy Lamps" circuit on fuse # 15. With this fuse removed there was zero measureable current draw.
I verified that there were no lamps or known devices drawing power.

Does anyone know what the parasitic current draw should be on this vehicle?

I contacted several Ford dealers. No one knew what the current draw should be but said 0.7 amps sounded "in the ball park". One suggested that I come in for a $50 minimum battery test to confirm that I have a drain on my battery. Guess he wanted me to pay him to tell me what I already know.

Any other things to consider?

Thank you to anyone willing to offer a comment that might help.

Don

 

[BrooklynBay]

Welcome to this forum! The clamp on meters usually only test AC current. What model do you have that is capable of reading DC current draw with a clamp on attachement? The memory circuit is providing memory for the radio as well as the computer. If you have other systems like keyless entry, it will need constant power to be able to detect the keypad. These systems are in stand by mode. The battery deep cycled, and needs to be charged slowly, just the same way like it got drained. It's possible that the constant drain might have ruined the battery, but the only way to tell is if you slow charge it first.

 

[dtf99]

Thanks for your response.
I have a Fluke 336 Clamp Meter. It is able to read AC volts and amps as well as DC volts and amps. It is a great tool!
I did a similar current draw reading on a 2000 Honda Accord and read only 0.1 amps of current so think that the 0.7 amps I am seeing on the Explorer is a bit excessive but don't know for sure since the Ford dealers I called didn't know what the actual spec is. Hopefully someone on the forum will have that information.
Thanks again,

 

[BrooklynBay]

Do you know anybody with a similar vehicle like your Explorer? You could do a comparison check.

 

[dtf99]

Don't know anybody with a 2004 Explorer. Maybe I should roam the used car lots and ask to take a peek under the hood.

 

[BrooklynBay]

http://www.explorerforum.com/forums/showpost.php?p=2081752&postcount=3. BTW, I've just moved this thread to the stock 02-05 section.

 

[coonhunter]

I installed a relay to dis able the same circuit you are having problems with hasn't seemed to affect anything except for when I forget my keys which are different for the doors.

 

[jp450]

That sounds about right on the current draw.
I have an 07 Rustang GT that when it sits for a month or so will be dead. To prevent this I put a conditioner on the battery. Our 04 F150 at work will be dead in about 3 weeks if it is not used.

 

[waskly]

if storing a vehicle over a month, you should disconnect the battery, also the meter you are using is inaccurate for automotive. i know all clamp meters, for automotive draws, at sub 1 amp are not reliable.

 

[jp450]

In our case with the Mustang, which does not get driven in the winter months, we can not remove the battery because at times we need to pull it out of the garage to access other things. The charger that I got is a "Smart" charger that keeps the battery charged without over doing it. We have been doing this since 2007 without any problems.

 

[scottfab]

Thanks for your response.
I have a Fluke 336 Clamp Meter. It is able to read AC volts and amps as well as DC volts and amps. It is a great tool!
I did a similar current draw reading on a 2000 Honda Accord and read only 0.1 amps of current so think that the 0.7 amps I am seeing on the Explorer is a bit excessive but don't know for sure since the Ford dealers I called didn't know what the actual spec is. Hopefully someone on the forum will have that information.
Thanks again,

Your meter is accurate enough for such a test. The differential current sensitivity test you did between the two cars proves this. I agree 0.7 amp is high. My Chevy draws 0.1amp so I put a float charger on it in the winter (it is unused over winter). I will measure my 03 Explorer tomorrow since I will be in the eng compartment anyway. Will post then.

 

[matt0248]

O/P. how long did you take you reading for? Sometimes it can take 20-30 minutes for some of the electronics to go to "sleep." 0.7 VDC is a little high but not excessive. I would expect around 0.5 VDC or less. All the electronics on that circuit have parasitic draw to keep the memory alive. So it may be normal. Espically if it sat for so long.

 

[waskly]

Your meter is accurate enough for such a test. The differential current sensitivity test you did between the two cars proves this. I agree 0.7 amp is high. My Chevy draws 0.1amp so I put a float charger on it in the winter (it is unused over winter). I will measure my 03 Explorer tomorrow since I will be in the eng compartment anyway. Will post then.

a camp meter is not accurate at all its for high voltage not sub 1 amp reading. this is why a multi meter is 10/20amp and clamp meters goto 400/600/800/1000

 

[matt0248]

a camp meter is not accurate at all its for high voltage not sub 1 amp reading. this is why a multi meter is 10/20amp and clamp meters goto 400/600/800/1000

They make clamp-on style meters in the mA range that work with a DVOM and work just fine and are jsut as accrate as breaking the circuit and running the curring through the DVOM. I have them and use them all the time. Yes, if the clamp/meter is designed for 10/20A range it will not be accurate for mA ranges. But, if you have the right one it will work.

 

[thedogzeus]

O/P. how long did you take you reading for? Sometimes it can take 20-30 minutes for some of the electronics to go to "sleep." 0.7 VDC is a little high but not excessive. I would expect around 0.5 VDC or less. All the electronics on that circuit have parasitic draw to keep the memory alive. So it may be normal. Espically if it sat for so long.

Actually 0.5-0.7 is VERY high. Standby drain should be no more than 50mA (0.05 amp). And VDC = voltage DC and we are measuring current here not voltage.

When modules are in standby mode ( the 30 mins after shutting down car and having all doors closed and locked etc), current draw will be in the order of 300-500mA (0.3-0.5 amp). Once the modules have timed out and gone to "sleep", the current draw should drop to the acceptable range of 20-50mA (0.02-0.05 amp).

To measure this without waking the modules, when you remove the earth terminal, make sure your meter is on and the probs are attached to the lead and terminal, hence keeping the circuit closed whilst removing the terminal.

Remember, if you open a door or disconnect the battery, the modules will "wakeup" and you will need to wait out the standby period again.

 

[matt0248]

Actually 0.5-0.7 is VERY high. Standby drain should be no more than 50mA (0.05 amp). And VDC = voltage DC and we are measuring current here not voltage.

When modules are in standby mode ( the 30 mins after shutting down car and having all doors closed and locked etc), current draw will be in the order of 300-500mA (0.3-0.5 amp). Once the modules have timed out and gone to "sleep", the current draw should drop to the acceptable range of 20-50mA (0.02-0.05 amp).

To measure this without waking the modules, when you remove the earth terminal, make sure your meter is on and the probs are attached to the lead and terminal, hence keeping the circuit closed whilst removing the terminal.

Remember, if you open a door or disconnect the battery, the modules will "wakeup" and you will need to wait out the standby period again.

yes mA ont VDC, that was my brain fart. There is generally no need to disconnect anything if you have an inductive ammeter that can read in mA's for your DVOM. That is what I have always done.

 

[scarytree]

Actually 0.5-0.7 is VERY high. Standby drain should be no more than 50mA (0.05 amp). And VDC = voltage DC and we are measuring current here not voltage.

When modules are in standby mode ( the 30 mins after shutting down car and having all doors closed and locked etc), current draw will be in the order of 300-500mA (0.3-0.5 amp). Once the modules have timed out and gone to "sleep", the current draw should drop to the acceptable range of 20-50mA (0.02-0.05 amp).

To measure this without waking the modules, when you remove the earth terminal, make sure your meter is on and the probs are attached to the lead and terminal, hence keeping the circuit closed whilst removing the terminal.

Remember, if you open a door or disconnect the battery, the modules will "wakeup" and you will need to wait out the standby period again.

 

[scarytree]

I agree with “thedogzeus”, my 2003 Exe did as he described. Pulling fuse 15 in the engine bay does remove the 0.3 amps immediately but follow “thedogzeus” test. My Exe’s amps reduced to .020 amps after the 30 minutes. I was worried after putting in a new battery and saw 0.3 amps drain from the battery. The best price I could get for the N65D in Sydney, Australia was $225-.

 

[87gt50]

On my -02 4.6 Limited I found a parasitic draw through the no 18 fuse, which seems to power one of the 4x4 modules. (A relay or something seems to get stuck...) With the fuse in, I have an empty battery within less than 2 days. Could anyone with a wiring diagram or knowledge please tell which module this is, as there seems to be more than one if I understand it correctly? I can drive the car, but am missing the auto 4x4 now when the winter is here.
Sorry if hijacking the thread, but it feels related to the subject.

Merry Christmas to you all!

 

[dejavouxdoux]

I'm having the same problem on my 04 Explorer. Got up one morning and the 3 month old battery was totally dead. Charged the battery and the ***** wouldn't start.

The PCM lost it's memory and I had to get a locksmith to come out and reprogram the PATS with a new key. 180.00

The nominal current draw should be no more than .050A. It has a .66A draw. Traced the draw to fuse #15 in the engine compartment. It's the Memory (PCM/DEAT/Cluster), Courtesy Lamps circuit.

Still looking for the problem. I'll let you know what I find.