Guide to Disabling Auto Start Stop + Removing the Auxiliary Battery on a 2025 RAM 1500 SO/HO

[Dodge1Ram]

Does your aux battery negative have a sensor like the primary battery negative does ? This sensor is for battery monitoring and charging. My 25 rebel base not even level 1 does not have a negative lead sensor for the aux battery only the main. This is likely why you get the error since the sensor notices the aux battery isn't there.

I did not have a sensor on my Aux battery either.

 

[Dodge1Ram]

I did not have a sensor on my Aux battery either.

Like you only sensor was on the Main Battery

 

[firemedic10584]

I did not have a sensor on my aux battery either, only one ground cable and one positive cable.

 

[firemedic10584]

Just an update - my truck does throw a CEL if I allow the start/stop to engage. I tried to pull whatever code it's throwing, but my (cheap) reader says no codes. I do an erase all codes and it clears it. Another user on the facebook post about this reported his truck wouldn't start back up after the start/stop engaged. Mine did start back up luckily. Any thoughts on this?

 

[Carlos.33193]

Just an update - my truck does throw a CEL if I allow the start/stop to engage. I tried to pull whatever code it's throwing, but my (cheap) reader says no codes. I do an erase all codes and it clears it. Another user on the facebook post about this reported his truck wouldn't start back up after the start/stop engaged. Mine did start back up luckily. Any thoughts on this?

The code i've seen on mine is Starter Relay 3 stuck off. On mine (L2) with the two sensors, it won't start back up if the 2nd battery is not connected or if not tied to the main battery like what I did.

I think this is best used in combination with an auto-start stop eliminator.

 

[RedFred]

Looks like I will just stick to installing the stop start eliminator instead of trying this mod.,

 

[firemedic10584]

Looks like I will just stick to installing the stop start eliminator instead of trying this mod.,

I do think the aux battery delete and adding the larger H8 group size battery is better for the truck. But also add the start stop eliminator or just remember to turn it off when you get in the truck each time.

 

[RedFred]

I do think the aux battery delete and adding the larger H8 group size battery is better for the truck. But also add the start stop eliminator or just remember to turn it off when you get in the truck each time.

Not if it could potentially be throwing codes. It's not worth it to me. I haven't had any battery issues so no need to mess with it just for the sake of going with a larger battery. The thing that was of most interest to me was eliminating the start stop feature.

 

[BowDown]

Looks like I will just stick to installing the stop start eliminator instead of trying this mod.,

Yeah, this seems like a lot of trouble for nothing with the risk of more problems.
If AS/S bother me enough, I'll buy the harness

 

[firemedic10584]

Yeah, this seems like a lot of trouble for nothing with the risk of more problems.
If AS/S bother me enough, I'll buy the harness

I would disagree with it causing a risk of more problems. My truck now rests at a 12.5-12.7v when off and a steady 14.3v when running. I haven't had any sluggish starts or thought of the truck not starting. My truck sat for about 5 days a couple of weeks ago, and when I came back, it fired right up. I do know when I had the stock batteries in it, my truck would be UNDER 11v when I initially fired it up, but it still seemed to fire up fine. But these are just one big computer system. Any random thing can cause them to act up, I suppose.

 

[SW Driver]

Yeah, this seems like a lot of trouble for nothing with the risk of more problems.
If AS/S bother me enough, I'll buy the harness

When AS/S bothers me, I just press the button to turn it off. Such a simple solution. Ram even put the button in a convenient position so it’s simple to press the starter button to start the truck and then press the AS/S off button.

 

[turbom5]

Hey guys I'm reading your replies and I wish I had an answer but I don't. It worked on mine a level 0 rebel and the same method was posted by an rho owner who made downpipes for the HO.

I would disagree with it causing a risk of more problems. My truck now rests at a 12.5-12.7v when off and a steady 14.3v when running. I haven't had any sluggish starts or thought of the truck not starting. My truck sat for about 5 days a couple of weeks ago, and when I came back, it fired right up. I do know when I had the stock batteries in it, my truck would be UNDER 11v when I initially fired it up, but it still seemed to fire up fine. But these are just one big computer system. Any random thing can cause them to act up, I suppose.

I've had the same experience. I would always be at low 10.8 to 12 maybe but often in 11s. Now it's always in the 12s.

 

[BowDown]

I would disagree with it causing a risk of more problems. My truck now rests at a 12.5-12.7v when off and a steady 14.3v when running. I haven't had any sluggish starts or thought of the truck not starting. My truck sat for about 5 days a couple of weeks ago, and when I came back, it fired right up. I do know when I had the stock batteries in it, my truck would be UNDER 11v when I initially fired it up, but it still seemed to fire up fine. But these are just one big computer system. Any random thing can cause them to act up, I suppose.

I bought my 25 in September, it sat for 2 weeks while I still had the rental and waited for a PPF appointment, not one battery issue. Looking at this thread, the reviews of this being problem free seem mixed and it certainly is in FB groups where it's also posted. I disabled proximity on day one, my battery has always been at 12+V when Ive bothered to check it and in the high 13's when running. I only see 14V after a cold start and then only for a few miles
If it works for you and you like it, great. To me it seems more trouble than it's worth and I carry a NOCO jump box with me after the battery in my 20 died one night without warning so dead batteries are a real concern to me.

 

[BowDown]

When AS/S bothers me, I just press the button to turn it off. Such a simple solution. Ram even put the button in a convenient position so it’s simple to press the starter button to start the truck and then press the AS/S off button.

Well, if it bothered me enough to turn it off, I'd push the button to disable it. I've only used it (button) once to see if the 25 truck (AS/S) maintained its last state. AS/S doesn't bother me enough to even push the button.

 

[2025Rebelguy]

I just replaced my 2025 Rebel with a 2026 Rebel GT. It has the level 2 package but not auto steering, just lane keep assist. if nothing else, I now know how to get rid of the auxiliary battery in my Rubicon! Although it hides UNDER the main battery, so I was able to go with the larger main battery when I replaced them after 3 years of use. Hopefully this trick works, I hate the AS/S.

 

[RedFred]

I just replaced my 2025 Rebel with a 2026 Rebel GT. It has the level 2 package but not auto steering, just lane keep assist. if nothing else, I now know how to get rid of the auxiliary battery in my Rubicon! Although it hides UNDER the main battery, so I was able to go with the larger main battery when I replaced them after 3 years of use. Hopefully this trick works, I hate the AS/S.

They do sell the auto start stop disabler harness. I purchased one but still haven't installed it.

 

[turbom5]

They do sell the auto start stop disabler harness. I purchased one but still haven't installed it.

Yea and AliExpress sells harnesses like that for 2024 and earlier trucks for pennies on the dollar. I don't support paying 100usd for such a harness and have more enjoyment trying to figure out a way around it through coding or means like this. Those harnesses are way over priced imo.

 

[tinfoil_hat]

They do sell the auto start stop disabler harness. I purchased one but still haven't installed it.

I just installed one last week. It took longer to watch the video than it did to install.

Yea and AliExpress sells harnesses like that for 2024 and earlier trucks for pennies on the dollar. I don't support paying 100usd for such a harness and have more enjoyment trying to figure out a way around it through coding or means like this. Those harnesses are way over priced imo.

It's a one time purchase and the build quality seems to be excellent. $100 fair, in my opinion.

 

[Mr.Grid]

Do the 2025-26 start / stop system no longer use the 48v system (battery behind rear seat back) that was in the 2024 and previous eTorque trucks? Following this thread and not up to date on this 12v S/S system.

 

[tinfoil_hat]

Do the 2025-26 start / stop system no longer use the 48v system (battery behind rear seat back) that was in the 2024 and previous eTorque trucks? Following this thread and not up to date on this 12v S/S system.

2025-2026 electronics are a total departure from 2019-2024.