Parasitic Battery Drain/Demand Lamp Fuse

[cparrish]

I have a 2118 Explorer XLT with a parasitic battery drain that kills it in 72 hrs. Was checking watts while pulling the distribution and under-dash fuses one at a time to find the culprit. In doing so I found there is no fuse in under-dash fuse #1 location (demand lamp/battery saver) and it won't hold one when I try to put one in it. Possibly at one time the previous owner tried to force a larger fuse into this location and damaged the terminals, which due to housing and location I can't see. Had the car, and problem, for two years and everything works okay. What is the fuse for? Being called battery saver I'm wondering if this could be the answer to my problem.

 

[ProjectSHO89]

Fuse position #1 in the BCM is not used in your year and model.

 

[cparrish]

Fuse position #1 in the BCM is not used in your year and model.

Okay, was going by the owner's manual. But like I said everything works correctly without it.

 

[JohnelP]

Right on time on this topic. It was for long on my mind, but today put more attention to it.
I have noticed historically the battery does not last longer than two 1/2 years on average. Except the last battery that was AGM and lasted longer. Until today, car started normally at home, stayed at the grocery store for about 30 min, returned to the car, and it refused to start. Jump started it and brought it home. I measured the current draw after stopping the car and I have noticed that for about 2 minutes draws between 2 to 3amps, then all the circuits enter the sleep mode and the current draw gets to 0.5Amps and stays like that.
I recall I did a similar measurement on my old Honda Accord, and that one was drawing 0.1A when sleep.

What kind of sleep mode current draw measurements did you read? Is 500mA "normal" with explorers? or do i have a faulty circuit somewhere?

 

[cparrish]

Right on time on this topic. It was for long on my mind, but today put more attention to it.
I have noticed historically the battery does not last longer than two 1/2 years on average. Except the last battery that was AGM and lasted longer. Until today, car started normally at home, stayed at the grocery store for about 30 min, returned to the car, and it refused to start. Jump started it and brought it home. I measured the current draw after stopping the car and I have noticed that for about 2 minutes draws between 2 to 3amps, then all the circuits enter the sleep mode and the current draw gets to 0.5Amps and stays like that.
I recall I did a similar measurement on my old Honda Accord, and that one was drawing 0.1A when sleep.

What kind of sleep mode current draw measurements did you read? Is 500mA "normal" with explorers? or do i have a faulty circuit somewhere?

About 50ma is typical, but I'm at about 200 after sitting for awhile.

 

[JohnelP]

Thanks.
By the way, the way i try to identify which circuit drains the current is the following:
disconnect the negative cable and connect a multimeter on the 10A setting between the disconnected cable and the battery terminal. And then on the fuse panel I start to remove one fuse at a time, until i find the one that stops the parasitic current draw. then you know which circuit to investigate deeper.

 

[ProjectSHO89]

In order to prevent mis-diagnosis, it is critical that you follow the CORRECT testing procedure and you must include an understanding of the TIMING that is used in the vehicle's power-down logic. Failure to account for this timing element will usually cause wasted time and money.

Here is the procedure from the 2018 Explorer factory service manual. Read the whole thing, several times if necessary, and make sure you fully understand it before you pick up any tools.

 

[JohnelP]

tha

In order to prevent mis-diagnosis, it is critical that you follow the CORRECT testing procedure and you must include an understanding of the TIMING that is used in the vehicle's power-down logic. Failure to account for this timing element will usually cause wasted time and money.

Here is the procedure from the 2018 Explorer factory service manual. Read the whole thing, several times if necessary, and make sure you fully understand it before you pick up any tools.

thanks for the document! helps a lot!

 

[cparrish]

2018 Ford Explorer XLT. I'm trying to find the source of a parasitic drain. After following shutdown procedures, I pulled every fuse and relay in the distribution box and under the dash. It still has a 200 mA drain with no fuses in the boxes. I've checked the alternator and the diodes are fine. The only way to eliminate it is to disconnect the smaller cable off the positive battery post, which I assume feeds the computers. Any suggestions from the group?

 

[mr.badwrench]

Amazon product ASIN B08MTY51R4I have a meter similar to the one linked. It can measure DC amps as a clamp meter. It's a fussy thing. I have to hold it near the wire and zero it to cancel Earth's magnetic field then hold it the same way while putting the clamp around the wire. It helped me find a draw in my Expedition.

 

[SuburbanDad]

200 mA is not a lot of power. Do you not drive the vehicle enough? Maybe a battery tender to keep it topped off and just forget about the drain.

 

[cparrish]

200 mA is not a lot of power. Do you not drive the vehicle enough? Maybe a battery tender to keep it topped off and just forget about the drain.

Ford specs on this vehicle state that the max acceptable is 50 mA and anything higher denotes a problem. The battery will drain in about 72 hours.

 

[ProjectSHO89]

Why did you start a new thread for this? You started one last week for the same thing and there were explicit instructions provided in it.

 

[cparrish]

Why did you start a new thread for this? You started one last week for the same thing and there were explicit instructions provided in it.

Sorry. I should have stayed on the same thread, but thought I posted the original in another forum. I followed the instructions and found nothing is being drawn from the distribution box or under-dash fuse panels. Trying to figure out the next step in diagnosing the problem. I'm assuming a computer is not going into "sleep mode", but don't know how to verify it.

 

[peterk9]

The 2 threads have been merged. BTW, I believe you have a 2018, not a 2118.

Peter

 

[56_F100]

The 2 threads have been merged. BTW, I believe you have a 2018, not a 2118.

Peter

Peter,
I figured cparish had a REALLY new Explorer and Ford had started using a new fangled hyperdrive spacewarp approach in the circuitry. (I couldnt leave it alone)