Parking Lamp Circuit Parisitic Draw

[tdd5024]

Good Evening All,

New (to me!) ranger owner here, doing some DIY work to get everything running correctly. It's a 97 4.0 with about 245,000 miles and there has not been much done in terms of aftermarket parts aside from an updated radio. I recently changed out the fuel filter and returned to work on the truck two weeks later to find that the battery was not strong enough to initiate crank. An overnight trickle got the battery up to snuff, and then I did a parasitic draw test to find out where I'm losing juice. Turns out pulling the #8 20 amp maxi fuse under the hood removes the draw and the battery has been fine ever since. After doing a few other fixes I returned to attempt to fix the parasitic draw which is coming up as the parking lamp circuit. My first inclination was to look at the thing that I recently changed - the fuel filter. I removed the connection to it and replaced the fuse to see the same draw coming from the battery. It's approximately 170 mA, but when I remove the fuse it goes down to 20 mA. I also purchased new external light bulbs to see if any of them were creating an excessive draw, but swapping out all of them resulted in the same draw when the fuse is put back into place. The last thing I did was remove the electrical connector for a trailer that was connected to the rear driver side brake light. I reconnected the original wires that were spliced and removed the fuse that was spliced into the wires. None of this has removed the draw, so I am currently at a loss as to what it may be.

Anyone have a good idea on how to approach this electrical gremlin?

 

[franklin2]

Here's the fuse in this diagram.

 

[franklin2]

Here's that one circuit it feeds.

 

[franklin2]

Here's the other circuit. I think I would pull fuse #3 in the fuse panel in the cab and see what the drain does then. Try to figure out is the drain on the circuit in the diagram below (fuse 3 in the cab) or the circuit above(fuse 27 in the cab).

 

[Fast Eddie]

Good evening. First, thank you for your service.

I'd like to point you to a recent post along the same lines. I'll send the direct link because I learned the testing process is critical to identifying the true source of the problem. In my case, it turned out to be a bad battery cell. The point is, I went through an elaborate testing process for a bad battery. Try this approach and post your result. I'll try to help from there: https://www.therangerstation.com/forums/index.php?threads/help-parasitic-draw-instrument-cluster.196421/post-1884878

The 170mA draw coincides with my .17A draw observed in initial troubleshooting. This was the result of things 'waking up' as I made the connection with the multimeter via connecting the neg battery cable to the neg battery post in an attempt to measure the 'parasitic' draw. Turns out, the multi meter acts a conduit and when the leads are initially connected, it fires up some connetions (e.g. ECM/PCM).

Hope that help some.

 

[franklin2]

I believe Ford says to make the truck go to sleep you need the key out, the doors closed, and then wait at least 30-40 min. Then you can look at the meter and see what it says. It's all to do with that battery saver relay in one of the diagrams above.

 

[tdd5024]

Thank you for your replies @franklin2 and @PanteraGT5S. I'm not convinced that this is a battery issue just yet, but I did some troublshooting based on the diagrams above. After putting the engine bay fuse #8 back in and making sure the doors were "closed" by turning the latches I pulled mini fuses #3 and #27. This action yielded no change, with a 150-170 mA draw when hooking up the multimeter in series with the battery cable and the battery terminal.

I then reinserted the mini fuses, with the #3 being inserted first followed by the #27. No change came with the #3 fuse, but when I inserted the #27 a rapid clicking and fizzling behind the instrument panel occurred. After I put it all the way in that stopped, but I checked the multimeter and it showed 1.5 on the multimeter, so 1500 mA. I tried to replicate and I got the clicking and fizzling, but no change on the multimeter. I may have fried something completely different than the original issue. Going to take a look at the diagrams again and see if I can find another potential culprit!

 

[alwaysFlOoReD]

Sometimes it takes up to 30 minutes for all the sensors to shut off.

 

[tdd5024]

@alwaysFlOoReD, I waited 45 minutes before I started the tests. I just did a little bit more troubleshooting and the draw goes away when I pull fuse #25 in the cab. Does anyone have the wiring diagram for the things on that circuit?

 

[franklin2]

Here is fuse 25. It says it feeds the GEM module and the instrument cluster. Be careful, sometimes these things can lead you in circles. That battery saver relay that puts the truck to sleep is usually controlled by the GEM.

 

[Fast Eddie]

I waited an hour. I also used a jumper cable between the battery cable and post so no 'new' connections would be made when I switched to the multimeter.

In this order:
1) Remove neg bat cable
2) Some kind of jumper between post and cable
3) Multimeter also between post and cable at this time
4) Door latches
5) Wait 1hr
6) Mulltimeter on
7) Remove jumper cable
8) Observe draw.

If draw continues, replace jumper cable, remove multimeter. It's important no new disconnects/connects are made during that process.
Start pulling fuses and measure draw between fuse terminals in an attempt to isolate specific fuse.

Go back and read the whole thread. There were other viable suggestions given for my problem (corrosion). It just wasn't my specific issue.
https://www.therangerstation.com/forums/index.php?threads/help-parasitic-draw-instrument-cluster.196421

Good luck.

 

[tdd5024]

I’ve made some progress, but I need some more information if anyone has any advice. I unplugged the GEM and found that the draw goes away completely. My next step was to try a replacement, so I ordered one that came in this past weekend. Swapped it out and plugged it in to find that the draw has returned.

Does anyone have a diagram for the GEM? It’s a rectangular plastic piece behind the radio. Has two connectors to it with a ton of wires! Any help is greatly appreciated.

 

[franklin2]

Here's the diagrams for the GEM. See the one with the battery saver relay? That was what I was saying about going in circles. The battery saver relay puts some of the truck's features to sleep. You have to wait for the GEM to de-activate the battery saver relay after the key is off and the doors are closed.

 

[Fast Eddie]

If he refuses to let connection ensue and the truck actually go to sleep (about 60min in my case), he'll continue 'going in circles'. If he's not doing the below, he's continually waking the system up every time he connects his meter between the neg past and bat cable.

In this order:
1) Remove neg bat cable
2) Some kind of jumper between post and cable
3) Multimeter also between post and cable at this time
4) Door latches
5) Wait 1hr
6) Mulltimeter on
7) Remove jumper cable
8) Observe draw

This will be my last contri to this thread

 

[tdd5024]

@PanteraGT5S and @franklin2 I am all ears now. I sincerely apologize for wasting your time and mine and I am open to any recommendations you have. The draw was typical for a resting vehicle at 0.01 after I did all of the above steps. My battery was dead after two weeks of sitting though, so I am not convinced that it was a light left on. I will leave the battery connected for now and see what it gets down to in a few days.

I must ask: What does all of this mean? Do I not have an electrical issue?