If you own a RAM 2500 or 3500 HD, you already know the drill. Every single time you start the engine, the auto start/stop system turns itself back on. You press the button to disable it, drive for a while, park, and the next time you fire it up, it’s reset to on again. It’s one of the most complained-about features on these trucks, and for good reason. Heavy-duty trucks with big diesel or gas engines aren’t exactly designed with stop/start in mind, and many owners find the constant shutting off and restarting rough, annoying, and hard on the drivetrain over time.
There are two ways to deal with this: press the button every single time you get in the truck, or use a plug-and-play eliminator module that handles it automatically. This guide covers both options, explains why the factory reset happens, and helps you pick the right fix for how you use your truck.
Using the Factory Dashboard Button
The RAM 2500 and 3500 HD both have a dedicated auto start/stop disable button on the center console or dash, depending on the trim and model year. It typically shows an “A” with a circular arrow and a small “off” indicator. Pressing it once disables the system for that drive cycle.
On most model years from 2019 onward, the system resets every time you cycle the ignition. That’s by design. FCA (now Stellantis) engineered it that way to meet fuel economy regulations. The truck defaults to start/stop-enabled on every cold start, regardless of what you set previously.
If your truck is a 2019 to 2024 RAM 2500 or 3500 HD, the button works the same way across both gas (6.4L Hemi) and diesel (6.7L Cummins) trims. Press it once after startup and the system stays off for that drive. But it will be back on tomorrow morning.
For most HD truck owners, pressing a button every single day gets old fast, especially if the truck is used for work and you’re jumping in and out multiple times a day. That’s where the eliminator module comes in.
The Permanent Fix: Start/Stop Eliminator Module
A start/stop eliminator is a small plug-and-play module that connects to your OBD2 port or a connector behind the dash. Once installed, it automatically sends the “disable” signal every time the truck starts, so you never have to press the button manually again. No wiring, no programming, no dealer visit needed.
For the RAM 2500 and 3500 HD specifically, you’ll want a module that’s confirmed compatible with your generation. The most common options on the market support the 2019 to 2024 model years. Some older eliminators designed for the RAM 1500 won’t work on the Heavy Duty because the signal architecture is slightly different, so make sure whatever you buy lists the 2500 or 3500 HD by name.
Installation typically takes under five minutes. You plug the module into the OBD2 port (located under the left side of the dash near the steering column), and that’s it. Some versions use a secondary harness that tucks behind a seat or into the center console for a cleaner look, but either way it’s not a permanent modification to your truck.
RAM 2500 3500 HD Start Stop Eliminator Module
A plug-and-play module that automatically disables auto start/stop on every drive without any button pressing or reprogramming.
One thing to keep in mind: these modules work by mimicking the button press signal, not by modifying your ECU or deleting any software. Your truck’s warranty won’t be affected, and the module can be unplugged at any time if you ever want to return to default behavior. If you’re already comfortable with small DIY installs like reading codes with an OBD2 scanner, this is an even simpler job.
Model Year Notes
Not all RAM HD trucks have start/stop. Here’s a quick breakdown by generation:
- 2019 to 2024 RAM 2500/3500 HD: Auto start/stop is standard on most trims with both the 6.4L Hemi and 6.7L Cummins. The eliminator module method works on all of these.
- 2018 and older RAM 2500/3500: These trucks did not have an auto start/stop system at all. You don’t need a module or a fix.
- Tradesman trims: Some base-level Tradesman configurations from 2019 to 2021 may not include start/stop, depending on equipment packages. Check your owner’s manual or look for the “A” button on the dash to confirm.
If you’re also a RAM 1500 owner and want to see how the platform compares across model years, our article on RAM 1500 years to avoid is worth a read before your next purchase decision.
Frequently Asked Questions
Will disabling auto start/stop hurt my RAM 2500 or 3500’s battery or fuel economy?
No. The system was designed to save small amounts of fuel at stoplights, but the benefit on a heavy-duty truck is minimal compared to a smaller passenger car. Many owners actually report that keeping start/stop disabled reduces wear on their starter motor and battery over time, since both components take a small hit every time the engine cycles off and on. Your fuel economy change will be negligible in real-world driving.
Is the eliminator module safe to leave plugged in all the time?
Yes. Reputable eliminator modules are designed for permanent installation. They draw minimal power and communicate passively with the vehicle’s system. Most owners leave them in year-round with no issues. If you ever take your truck in for a dealer service visit and want to avoid questions, you can unplug it in seconds since it uses no tools to install or remove.
If you’re thinking about other truck upgrades while you’re at it, take a look at our guide to using the bed utility features on the RAM 1500 for ideas that carry over to the HD platform as well.
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