Parasitic draw / control module issue?

[MrDad36]

Hello all, I am at a loss after everything I’ve tried, and even after reading all the forums I could so here’s what I’ve got, and input would be appreciated.

2019 ram 2500 bighorn, no power running boards.

About 2 months ago, push to start did nothing, a second time, nothing, third time the engine cranked and it started. I went to have the battery tested and the cca was low, even though that was not the problem because it wouldn’t even turn over, they said these trucks with push start won’t even try if voltage is too low. I bought a new battery and set it in the kitchen until I swapped it out. Truck was fine for about 4 weeks, so I wasn’t worried about it. This was obviously entering winter. This was also when I started driving the truck every day again, as opposed to every 2-3 days.

Then it got interesting. Went to leave and it cranked a little funky, but started. I told myself I’ll swap the battery when I get home an hour later. I wasn’t thinking and shut it off when picking up my son, and when going to head home, it just cranked and cranked but wouldn’t start. Looking back on it, that was the symptom of the low cca / battery needing replaced, but the voltage had to have been fine to even try, so maybe the problem really started as follows...?

I got a jump from a trash truck, and the guy hooked the leads up wrong on his end. I didn’t know… and think it was connected wrong for a few seconds. Once corrected and the truck started, all issue lights on the dash were on. I went straight home, swapped the battery, from there, the check engine light was on, but went out after 2 days. The third day, the truck wouldn’t start, nothing, no cranking, symptom of low voltage. My dad came over and gave me a jump start. I went and had the battery tested, battery’s fine, only code was low voltage.

The truck was fine for days at a time, and randomly would have the issue doing nothing when pushing the start button, but would actually turn over and start after 3 pushes.

I have been unsuccessful with milliamp checks because when I connect the battery lead in series, the truck comes to life and is too much for milliamp readings, and I can’t just switch from amps to milliamps without swapping lead ports. Plus, the amp reading is less than .1, but somehow shows OL in milliamps. I thought I found the problem when the glove box wouldn’t close all the way keeping the light on, so I just removed the bulb. For the first time, the battery voltage stayed at 12.6 volts overnight, instead of dropping down to about 12.1 volts overnight.

Then yesterday, I drove it 20 minutes away no problem, parked it. 2 hours later, nothing first two pushes, it started on the third push. While driving, I noticed the top glove box light is on. I’ve had the top glove box door open for 2 years since I’ve owned it, and never saw the light come on. I noticed if I close it almost all the way, the light goes out and I can then open it and it stays off. The next day, same thing, the light was on while driving. I parked, shut the truck off and was playing on my phone and when the radio shut off, that’s when I saw the usb ports illuminate, shortly after the dash illuminated “press brake and push to start” then as it went out, the top glove box light flickered, about 5 minutes later, same thing, and again 5 minutes later. Maybe because I (key fob) never exited the vehicle, or door was never opened? I went out this am, sat in the truck without starting it, and after about 5 minutes, the dash “press brake and push to start” came in for a few seconds and went out. Nothing after that. I'm going to do some more testing tonight.

During checks, and negative removed from battery, checking ohms to ground across all fuses, all have resistance except for the fuel pump, horn and ac clutch all which have 0 ohms (dead short / closed) to ground. Seems strange, since they all work?

Some people stated this problem with the dash push to start message staying on, or in relation to power running boards which I don't have. I realize there are many modules, but I am having a very hard time finding out what is actually going on and what could be dragging the voltage down overnight, intermittently too.

 

[H3LZSN1P3R]

Hello all, I am at a loss after everything I’ve tried, and even after reading all the forums I could so here’s what I’ve got, and input would be appreciated.

2019 ram 2500 bighorn, no power running boards.

About 2 months ago, push to start did nothing, a second time, nothing, third time the engine cranked and it started. I went to have the battery tested and the cca was low, even though that was not the problem because it wouldn’t even turn over, they said these trucks with push start won’t even try if voltage is too low. I bought a new battery and set it in the kitchen until I swapped it out. Truck was fine for about 4 weeks, so I wasn’t worried about it. This was obviously entering winter. This was also when I started driving the truck every day again, as opposed to every 2-3 days.

Then it got interesting. Went to leave and it cranked a little funky, but started. I told myself I’ll swap the battery when I get home an hour later. I wasn’t thinking and shut it off when picking up my son, and when going to head home, it just cranked and cranked but wouldn’t start. Looking back on it, that was the symptom of the low cca / battery needing replaced, but the voltage had to have been fine to even try, so maybe the problem really started as follows...?

I got a jump from a trash truck, and the guy hooked the leads up wrong on his end. I didn’t know… and think it was connected wrong for a few seconds. Once corrected and the truck started, all issue lights on the dash were on. I went straight home, swapped the battery, from there, the check engine light was on, but went out after 2 days. The third day, the truck wouldn’t start, nothing, no cranking, symptom of low voltage. My dad came over and gave me a jump start. I went and had the battery tested, battery’s fine, only code was low voltage.

The truck was fine for days at a time, and randomly would have the issue doing nothing when pushing the start button, but would actually turn over and start after 3 pushes.

I have been unsuccessful with milliamp checks because when I connect the battery lead in series, the truck comes to life and is too much for milliamp readings, and I can’t just switch from amps to milliamps without swapping lead ports. Plus, the amp reading is less than .1, but somehow shows OL in milliamps. I thought I found the problem when the glove box wouldn’t close all the way keeping the light on, so I just removed the bulb. For the first time, the battery voltage stayed at 12.6 volts overnight, instead of dropping down to about 12.1 volts overnight.

Then yesterday, I drove it 20 minutes away no problem, parked it. 2 hours later, nothing first two pushes, it started on the third push. While driving, I noticed the top glove box light is on. I’ve had the top glove box door open for 2 years since I’ve owned it, and never saw the light come on. I noticed if I close it almost all the way, the light goes out and I can then open it and it stays off. The next day, same thing, the light was on while driving. I parked, shut the truck off and was playing on my phone and when the radio shut off, that’s when I saw the usb ports illuminate, shortly after the dash illuminated “press brake and push to start” then as it went out, the top glove box light flickered, about 5 minutes later, same thing, and again 5 minutes later. Maybe because I (key fob) never exited the vehicle, or door was never opened? I went out this am, sat in the truck without starting it, and after about 5 minutes, the dash “press brake and push to start” came in for a few seconds and went out. Nothing after that. I'm going to do some more testing tonight.

During checks, and negative removed from battery, checking ohms to ground across all fuses, all have resistance except for the fuel pump, horn and ac clutch all which have 0 ohms (dead short / closed) to ground. Seems strange, since they all work?

Some people stated this problem with the dash push to start message staying on, or in relation to power running boards which I don't have. I realize there are many modules, but I am having a very hard time finding out what is actually going on and what could be dragging the voltage down overnight, intermittently too.

You need a decent DVOM that will auto sense the amps and change from Amps to milliamps. You need to see what the draw is then start the diagnostics from there. This is where a power probe can be handy too

 

[MrDad36]

You need a decent DVOM that will auto sense the amps and change from Amps to milliamps. You need to see what the draw is then start the diagnostics from there. This is where a power probe can be handy too

I’m going to have to Google one of them, I’m guessing they’re expensive? As we speak, I’m driving, and every so often I keep noticing the top glove box light is on, I partially close it to get it to go out and open it again, only to notice it’s on again at some point.

 

[flan]

Diesel?

Did you replace both batteries or just 1 if so?

 

[Rockcrawlindude]

I’m going to have to Google one of them, I’m guessing they’re expensive? As we speak, I’m driving, and every so often I keep noticing the top glove box light is on, I partially close it to get it to go out and open it again, only to notice it’s on again at some point.

This is a fairly cheap Klein that does milliamp I’ve used it to check flame rectification and I’ve done parasitic draw milliamp tests with it

 

[MrDad36]

I only have one and it’s not a diesel.

I’m starting to wonder if this has nothing to do with the battery connected wrong during the jump? Perhaps it’s coincidental that my bottom glovebox got stuck ajar not closing the switch keeping the light on, and sometimes, the top glove box light gets stuck on too? Even though I’ve had the top glove box open for two years, I’m starting g to think it’s a simple on off switch, and that the computer is not keeping it off when partially closed them opened like I thought it was. And now the switch is finicky and more than less actually working like it should by turning the light on since it’s open?

 

[MrDad36]

I have one similar to that, The problem is when I disconnect the negative from the battery to wire this in series, as soon as I connect it, the truck goes through its wake up process, the other problem that I have is trying to switch from the 10 amp reading lead connection to the milliamp lead connection, not only does that break the circuit and wake the truck up again when I reconnect it, but at that point, the milliamp reading is out of range and won’t read.

 

[MrDad36]

You need a decent DVOM that will auto sense the amps and change from Amps to milliamps. You need to see what the draw is then start the diagnostics from there. This is where a power probe can be handy too

I thought you meant something that hooks up to a laptop that records a current through the night. I was driving and mis read DVOM.

 

[H3LZSN1P3R]

I have one similar to that, The problem is when I disconnect the negative from the battery to wire this in series, as soon as I connect it, the truck goes through its wake up process, the other problem that I have is trying to switch from the 10 amp reading lead connection to the milliamp lead connection, not only does that break the circuit and wake the truck up again when I reconnect it, but at that point, the milliamp reading is out of range and won’t read.

My Fluke meter only has one spot for amps and is auto range sensing so when i connect it it starts out on amps but as the draw drops it switches to the milliamp range.

 

[Rockcrawlindude]

I have one similar to that, The problem is when I disconnect the negative from the battery to wire this in series, as soon as I connect it, the truck goes through its wake up process, the other problem that I have is trying to switch from the 10 amp reading lead connection to the milliamp lead connection, not only does that break the circuit and wake the truck up again when I reconnect it, but at that point, the milliamp reading is out of range and won’t read.

Connect the battery, leave the hood open and Let the truck sit long enough for it to go back to sleep?

 

[H3LZSN1P3R]

Connect the battery, leave the hood open and Let the truck sit long enough for it to go back to sleep?

With a proper meter he could do that but i am guessing he would blow the milliamp fuse doing this with his meter.

 

[MrDad36]

With a proper meter he could do that but i am guessing he would blow the milliamp fuse doing this with his meter.

Correct, I can not keep the meter connected in series with the battery u til it sleeps because it starts out with too much current for the milliamp setting on my current meter. Once I get a better meter, I can do this.

 

[MrDad36]

At this point, I’m getting some major inconsistencies with the dash waking up. I don’t think I have a problem device drawing too much amps, I believe I have a problem module waking up the dash, or a problem switch telling the module to wake up the dash. I don’t know if I’ll be able to find it. And I know how this is gonna go taking it to the dealer… time without my truck, a large amount of $ spent, to more than likely not have the problem resolved.

 

[MrDad36]

I’m ready to find a nice cliff to roll this thing off of

 

[Rockcrawlindude]

With a proper meter he could do that but i am guessing he would blow the milliamp fuse doing this with his meter.

Why does he have to keep the meter hooked up? I think I got confused as to what we were trying to do.

You can do a Millivolt drop test across the fuse and look at a chart online to see how many milliamps are moving thru that fuse based on your millivolt drop. Which Is what I thought he wanted to do.

That’s how I found the parasitic draw on my Porsche which was keeping the window motor solenoid circuit powered at all times. Turned out to be the door switch. Normal function is the window can be powered until the door is opened and then power is cut but it was never seeing the door opened.

 

[H3LZSN1P3R]

Why does he have to keep the meter hooked up? I think I got confused as to what we were trying to do.

You can do a Millivolt drop test across the fuse and look at a chart online to see how many milliamps are moving thru that fuse based on your millivolt drop. Which Is what I thought he wanted to do.

That’s how I found the parasitic draw on my Porsche which was keeping the window motor solenoid circuit powered at all times. Turned out to be the door switch. Normal function is the window can be powered until the door is opened and then power is cut but it was never seeing the door opened.

By doing a true parasitic draw test the meter is connected between the battery + post and the positive terminal so all the vehicle power is flowing through the meter so you need the initial connection where the draw is high sometimes 4-5amps but it will then level out and should be no higher than 85 milliamp it used to be 50milliamp but these newer vehicles have more components that stay live.


Your way works to find whats drawing but by doing a parasitic draw test you can see if you have a draw on the system or not.

Also for the novice an ill advised way but still effective is do the parasitic draw test if the draw is too much then start pulling fuses/ reinserting fuses one by one to see which circuit has the draw when the meter shows the normal voltage you know where to look for your draw.

 

[MrDad36]

Why does he have to keep the meter hooked up? I think I got confused as to what we were trying to do.

You can do a Millivolt drop test across the fuse and look at a chart online to see how many milliamps are moving thru that fuse based on your millivolt drop. Which Is what I thought he wanted to do.

That’s how I found the parasitic draw on my Porsche which was keeping the window motor solenoid circuit powered at all times. Turned out to be the door switch. Normal function is the window can be powered until the door is opened and then power is cut but it was never seeing the door opened.

You are correct, I can do that to find the parasitic draw. I got hung up trying to see what the milliamp draw overall was before doing that though. I thought I had the problem with the bottom glove box light, but now I’m realizing the light would shut off once the truck goes to sleep, so that wouldn’t have been it. Plus, since all of this, I am now seeing the bigger problem is something telling the truck to wake up randomly, and intermittently, so far from what I’ve been able to see, or catch, has only been shortly after shutting the truck off.

 

[H3LZSN1P3R]

You are correct, I can do that to find the parasitic draw. I got hung up trying to see what the milliamp draw overall was before doing that though. I thought I had the problem with the bottom glove box light, but now I’m realizing the light would shut off once the truck goes to sleep, so that wouldn’t have been it. Plus, since all of this, I am now seeing the bigger problem is something telling the truck to wake up randomly, and intermittently, so far from what I’ve been able to see, or catch, has only been shortly after shutting the truck off.

Put your fob 15+ feet from the truck then see if the truck keeps waking up.

 

[MrDad36]

Put your fob 15+ feet from the truck then see if the truck keeps waking up.

I’ll try that tomorrow. FYI, the other day, with the fob on me, the truck woke up three times in a row about 2-5 minutes apart. Tonight, it only woke up once… same procedure. I’ll give some feedback with what it does tomorrow with the fob in the house.

 

[RJ1972]

I went that route with my 19 1500 Rebel. Even took the battery off and ran to O'Reilly's. They said battery test "Great". Do a parasitic draw test. I went round and round with it. I kept reading how crappy the Ram's batteries are.
I just ended up replacing it. Never an issue after that...at least for the 5 months I owned it. Then traded in for 23 2500 Big Horn.
Best of luck.