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Electrical problem/ground fault


Happy Camper

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Hi guys,

I'm running down low on ideas/solutions to solve an electrical (wich I believe to be a serious ground fault) problem on my 98 B-4000 4.0L (Manual transaxle, 4X4).

Any help will be appreciated.

Let me start by the symptoms:

While driving at low speeds in the woods at night coming back from my shack, I noticed that the headlights were dimming (blinking) and were also loosing intensity (brightness). I had the heater fan running at the same time and I also noticed that the revolutions of the fan motor were dropping at the exact same time that the headlights were dimming down. Cherry on the cake: I could ear some weird noises from hell from the radio also at the exact same time the headlights would be dimming down. A couple days ago, it got to a point where that dimming/decrease in fan motor rpms and radio issues last for 10-15 seconds. This situation happens each and every time I go to my shack when I run trough a lot of bumps at low speeds.

Also, last summer, my battery was dead after the truck sat for two months. At this time, I simply jumped-started the truck and didn't make a case out of it as I figured it was normal after two months of sitting. But recently, as temperatures are getting below freezing point with the upcoming winter, the battery gets dead after only a couple days of sitting.

So, I figured I have a ground fault (probably a wire touching the frame somewhere) that drains my battery when the truck sits for a while. Correct me if I'm wrong but I suspected systems that are always supplied with power even when the contact is "OFF" because the battery gets drained when the truck sits...

For now, as I can't find the problem I've taken the habit to disconnect the battery positive terminal whenever I know the car will sit for more than a day, wich is quite annoying...Doing so, I noticed some small sparks taking place between the battery pole and the wire connector each time I connect/disconnect the cable, which means to me (again, correct me if I'm wrong) that a current is flowing trough even when I got the contact switch in the "OFF" position, which, to me, looks like a good confirmation for the ground fault theory.


Now, what I've done:

I've took apart my starter to both have a look at the wires/connections (they look fine) and see if those little sparks would still occur with the starter dismantled from the engine and they did. So as far as I am concerned, I figured the starter motor isn't related to the ground fault.

Also, I'm really not sure if it can be related but as many other ranger/B4000 owners, I have this problem of the "door ajar" staying on all the time thus keeping my interior lights on all the time as well (which I took off in order to prevent my battery to get drained). Because I tough this problem could be related to my ground fault issue, I tool apart both of the door trims and disconnected the connections for the switch to check the switches operation. On both sides, I had a closed switch (continuity) when the door was open and an open switch (no continuity) when the door was shut, which seems like correct operation of the switches to me... I also measured the resistance across each of the switch leads and the frame with a multimeter in order to look for some current that would "leak" to the frame by the switches but all 4 measures where of the scale (open circuit). So I figured the switches are not related to the ground fault...(that however doesn't explain why my "door ajar" sign remains on all the time knowing that the switches do work correctly. I'm now suspecting a faulty timer to keep the circuit closed (the timer that allows a delay between the moment that all doors are shut and the moment the interior light extinguishes)).

Finally, I had a look at a couple wires I could find but they honestly all look fine as they are inside one of those protective plastic shell. I also verified the power wire for my radio (aftermarket radio) to make sure it was in good shape and it is...


End of the story! (long one...sorry!)

So the question:

Have anyone experienced such a problem with the 4.0L or is awared of such an issue or at least have an idea on what I should look for next?

Feel also free to let me know if you need more precisions on what I've already done or if you think I've done something improperly...

Thank you for your time.
 


Rock Auto 5% Discount Code: F9A1A579ACFAD1: October 1st, 2021

shane96ranger

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I'm just curious why you took the starter motor apart for a charging issue?

I do think it sounds like you've got a ground issue. It very well could be inside your alternator. It also sounds like you need to do a load test and see if you have a circuit draining your battery.

Sasquatch_Ryda gave me a good "map" of how to pinpoint where a battery drain is coming from. Here it is below. Some of this is specific to my Escape (Smart Junction Box) but it is still useful information. Mine wound up being a poor connection that was draining the battery.

Component Tests
Battery — Drain Testing
WARNING: Do not attempt this test on a lead-acid battery that has recently been recharged. Explosive gases may cause personal injury. Failure to follow these instructions may result in personal injury.

NOTICE: To prevent damage to the meter, do not crank the engine or operate accessories that draw more than 10A.
NOTICE: If equipped with the CD6 audio unit, precautions must be taken when the battery has been disconnected. When reconnecting the battery, make sure no interruption of power occurs for 30 seconds. If power is interrupted during the first 30 seconds, permanent damage to the CD6 audio unit will result.
NOTE: No factory-equipped vehicle should have more than a 50 mA (0.050 amp) draw.
Check for current drains on the battery in excess of 50 mA (0.050 amp) with all the electrical accessories off and the vehicle at rest for at least 40 minutes. Current drains can be tested with the following procedure.
NOTE: Many electronic modules draw 10 mA (0.010 amp) or more continuously.
NOTE: Use an in-line ammeter between the negative battery post and its respective cable.
NOTE: Typically, a drain of approximately 1 amp is attributed to an engine compartment lamp, glove compartment lamp, or interior lamp staying on continually. Other component failures or wiring shorts are located by selectively pulling fuses to pinpoint the location of the current drain. When the current drain is found, the meter reading falls to an acceptable level. If the drain is still not located after checking all the fuses, it is due to the generator.
NOTE: To accurately test the drain on a battery, an in-line ammeter must be used. Use of a test lamp or voltmeter is not an accurate method due to the number of electronic modules.

  1. Make sure the junction box(es)/fuse panel(s) is accessible without turning on the interior lights or the underhood lights.
  1. Drive the vehicle at least 5 minutes and over 48 km/h (30 mph) to turn on and activate the vehicle systems.
  1. Allow the vehicle to sit with the key off for at least 40 minutes to allow the modules to time out/power down.
  1. Connect a fused jumper wire (30A) between the negative battery cable and the negative battery post to prevent modules from resetting and to catch capacitive drains.
  1. Disconnect the negative battery cable from the negative battery post without breaking the connection of the jumper wire.
  1. NOTE: It is very important that continuity is not broken between the battery and the negative battery cable when connecting the meter. If this happens, the entire procedure must be repeated.
    Connect the battery tester between the negative battery cable and the post. The meter must be capable of reading milliamps and should have a 10 amp capability.
  1. NOTE: If the meter settings need to be switched or the test leads need to be moved to another jack, the jumper wire must be reinstalled to avoid breaking continuity.
    NOTE: Amperage draw varies from vehicle to vehicle depending on the equipment package. Compare to a similar vehicle for reference.
    NOTE: No factory-equipped vehicle should have more than a 50 mA (0.050 amp) draw.
    Remove the jumper wire.
  1. Note the amperage draw. Draw varies from vehicle to vehicle depending on the equipment package. Compare to a similar vehicle for reference.
  1. If the draw is found to be excessive, remove the fuses from the smart junction box (SJB) 1 at a time and note the current reading. Do not reinstall the fuses until you have finished testing. To correctly isolate each of the circuits, all of the fuses may need to be removed and then install 1 fuse, note the amperage draw, remove the fuse and install the next fuse. Continue this process with each fuse.
  1. If the current draw is still excessive, remove the fuses from the battery junction box (BJB) 1 at a time and note the current drop. Do not reinstall the fuses until you have finished testing. To correctly isolate each of the circuits, all of the fuses may need to be removed, then install 1 fuse, note the amperage draw, remove the fuse and install the next fuse. Continue this process with each fuse. When the current level drops to an acceptable level after removing a fuse, the circuit containing the excessive draw has been located.
  1. Check the wiring diagrams for any circuits that run from the battery without passing through the BJB or the SJB. If the current draw is still excessive, disconnect these circuits until the draw is found. Also, disconnect the generator electrical connections if the draw cannot be located. The generator may be internally shorted, causing the current drain.
 
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Happy Camper

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Hi Shane,

Thank you for your answer, I don't have my meter on hand tonight but I will perform the "Sasquatch_Ryda" test as soon as possible and come back with results. Looks like a good way to pinpoint where the problem is...

For the starter, I took it apart to see if I would still get those little sparks across the battery positive pole and cable when they get close to each other when I connect/disconnect the cable. If no more sparks would have been observed, it would have been an indication of an internally shorted starter motor or solenoid...

Thanks again for you reply!
 

cvar

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Does the battery still drain when you pull out fuse 18 (ie, door locks)?
 

Happy Camper

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Hi cvar,

Hi went to pull #18 fuse but the slot is empty! I don't have the power door locks...might explain why I don't have that fuse!

Thanks anyways.
 

cvar

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What fuse provides power to your door switches? Pull that one.
 

adsm08

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You don't have a "ground fault". You have a parasitic draw which is what is tested for in the test Shane posted (Sasquatch_Ryda is the guy who posted the test). The sort of "ground fault" you described, known as a dead short and is more likely to result in a blown fuse than a dead battery.

Your loss of power may be a ground side resistance issue, or may be a loose wire on the alternator, or any number of other loose connections.


Last thing I have for input here, sparks when connecting the battery are normal. You will get more if something is turned on, but since some circuits, like radio and computer memory, are always powered, you will get some sort of sparking and that is not indicative of a grounding issue.
 

Happy Camper

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Hi again,

Some new input on that problem:

Last night, I found what is called in the owner's manual a battery saver relay. It is located under the dash panel in what seems to be called "auxiliary relay box 1". I found three relays in there (some slots are empty) that are all identical (ford part # F57B-14B192-AA). An other one of those relays (the top left one) controls the dome light. So, because they are all identical, I tried swapping the dome light relay for another one to see if that would shut the light (both in a doors closed, ignition OFF, key IN condition and doors closed ignition ON, engine running condition). Nothing happened...the light remains ON whatever the relay I put in the slot (I tried all three of them). As I would be surprised to have three bad relays at the same time, I don't think the problem is there (I found a couple explorer guys having a "parasitic draw" (Thanks adsm08! Feel free to correct me on language issues, english isn't my first language so I may write "strange" things sometimes...) stating that one of those relays in auxiliary relay box 1 was the source of the problem, most often the "battery saver relay").

Just an idea like that: could one of the door switches show normal conditions (open circuit with door shut and closed circuit with door opened) and still be faulty?

Also, I just remembered something which might be related to the problem (thanks again to adsm 08, your sayings on the dead short vs parasitic draw refreshed my memory...). When I bought the truck last spring, the seller told me that the dome light sometimes could take up to 30 minutes to go out after you shut the doors and that it was normal...(I am greatly questioning that statement now!). So, I bought the truck, drove approx. 200-300 km with it and let it sit for three weeks as I still had my other truck. Three weeks later, I drove it to my local shop to get an estimate for an exhaust fix. It started well and and I just drove the 2-3 km between home and the shop and parked the truck in the garage's yard because they would work on it only in the afternoon. So, when I got back to the garage to pick up the truck, surprise, the battery was dead. My mechanics even told me he had to jump start it to get it in the shop in the beginning of the afternoon. So, we jumped-started it again and it went fine. On my way home tough, I noticed both 4X4 hi and low range lights to be flashing in the instruments panel so I tried to engage it and nothing happened so I went back to the garage and number 26 10A fuse had blew up. Put back a new fuse and everything was ok. I had at this point a tough for the seller saying the 30 min. delay was normal so I pulled out the three bulbs of the dome light and I never had this dead battery issue again until now (except for what I described in my first post where the truck sat for two months last summer but it sat with the three bulbs removed from the sockets...).

According to the owner's manual, #26 fuse supplies:

Battery Saver Relay, Electronic Shift Relay,
Interior Lamp Relay, Power Window Relay,
Electronic Shift Control Module, Dome/Map
Lamp, GEM

This is the reason why I had a look for that "battery saver relay"...

Also, a couple days ago, I took the radio apart to make sure its constant 12V supply wire wasn't touching the frame and it looked fine. But after I did that (and maybe a few other checks as well), #26 fuse blew up again (4X4 lights flashing and impossible to engage 4X4 etc.).

I'm really starting to think that both my parasitic draw issue and dome light are related (I understand that they are both supplied by # 26 fuse). So, if the three relays I describe above appear to work fine, could the GEM be the source of the problem or am I getting it all wrong?

Anyways, I will perform tonight the "Sasquatch_Ryda test" and come back with the results tomorrow to make sure the draw comes from number 26 and not somewhere else. So, cvar, I will pull tonight # 26 and see if the current draw decreases as it is the one fuse supplying the door switches. OK for the sparks input adsm08, I just tough it wasn't normal to have such big sparks...

Finally, let me thank you for your help (especially for the reading of those ?%$%??&?$long posts! Apologies for that, the problem has many "aspects" to be described...). At least, I think your help gets me closer and closer to a fix!

Thanks again. Update on the test will come tomorrow night...
 
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Happy Camper

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Ok, did the test.

I read a 330mA draw after going trough all the steps of the test.

Started pulling the fuses. The results:

When I pulled # 25 fuse, the draw decreased to 262 mA.

When I pulled # 26, the draw cut down to 3mA. Gotcha!

I tried putting #25 alone (without 26) and the draw went back to 71 mA.

So, # 25 fuse circuit draws 68 mA and #26 fuse circuit draws 259 mA.

According to the manual, # 25 fuse (7.5 A) supplies GEM and instrument cluster (got a couple burned out lights in there, I wonder if it is related or not...)

#26 fuse (10A) supplies battery saver relay, electronic shift relay, interior lamps relay, power windows relay (mines are manual), electronic shift control module, dome/map lights and GEM.

Because I don‘t know where else to look for, I took both door trims off again and disconnected both door switches at the same time. Not only the draw remained buteven with thes switches disconnected (open circuit), I still had power on the dome lights...Strange!

So once again, I‘m stuck.

Question: How should I proceed to isolate each one of the sub-circuits?

Tkanks again
 

Crossthreader

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I did some poking around in the wiring diagrams, and this is what I came up with. Fuse 26 supplies the battery saver relay via a Tan/Yellow wire. All the other systems on this circuit are switched by the battery saver relay, so if they are still drawing current, it is because the relay is stuck on or the GEM is holding the relay on. Power out of the relay is on a Green/Orange wire, which is spliced in the main harness to connect everything else. A Violet/Orange wire from the GEM grounds the Battery Saver Relay to turn it on.

If you unplug the relay and connect a test light ground clip to battery power then probe Pin 2 of the relay, it should not light. If it does light, the GEM is trying to turn the relay on. To prove the test light connection, touch the probe to something that is ground and the light should light.

Hope this helps.

Paul
 

Happy Camper

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Hi Paul,

Thanks for that input. I have to mention tough that in that auxiliary box 1, I find three relays and a couple empty slots (w/o any electrical connections). I am not sure which one is what because I can't find the proper diagram. But, what I can tell for sure:

- two of those relays are quite hot all the times when compared to the third one.

- When I test those two relays with the test light as you suggested (pin #2), I do have a light on.

As mentioned in a previous post, I would be surprised two have two or even three bad relays at the same time (I tried swapping the three of them around as they are identical and it didn't had any effect on the draw...) so I really start to believe that you're leading me on the right track with that GEM failure...

Question: where can I find that GEM and how to test it?

Looks like we're getting up to something, thanks to everybody!
 
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shane96ranger

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I believe the GEM is located behind the stereo. However, I would start by doing the parasitic draw test, and eliminating the alternator as a suspect. With some of the symptoms you've described (lights dimming - radio noises - draining battery), that would be my first suspect.


Sent from a Commodore 64 using a 300 baud modem
 
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Happy Camper

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Hi again Shane,

Are you suggesting that the draw can still come from the alternator even tough it cut down to 3mA when I pulled both #25 and 26 fuses? (I did the test actually and this is what I came up with: 330 mA draw that cuts down to 262 mA when I pull #25 fuse and cuts even more down to 3mA when I pulled #26...) This is the reason why I suspect the GEM to be the source of the problem (you get the hole story if you read the last couple posts...)

That being said, I am pretty sure I have a problem with my GEM module but I am not sure it is my sole problem. All the symtoms you mentioned are triggered when I ride trough bumps at slow speeds (on quite rough terrain). So, I was more looking for a loose connections somewhere than a faulty GEM module... But, at the same time, the test Paul (Crossthreader) made me do with the test light was pretty concluent (enven more when combined with the fact that those two relays are pretty hot at all times). So the GEM gives power to those two relays when it should not. But can the GEM be also be the cause of headlights dimming/radio noises, etc. Maybe a loose connection on the GEM? What do you think?

Thanks

Simon
 

shane96ranger

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I apologize, I am on my phone, and I don't navigate so hot on it (using Tapatalk). I completely missed your testing results post. My bad.


Sent from a Commodore 64 using a 300 baud modem
 

Happy Camper

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Don't worry!

My posts are so long, it's quite understandable that you haven't read the hole thing! (especially on a phone...)

By the way, any suggestions on that GEM?

Thanks
 


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