Dodge RAM Alarm System Dead Due to Auxiliary Battery

I had a very similar issue with my 2015 Dodge RAM, and it turned out to be a failing auxiliary battery causing problems with the car alarm and electrical systems. After the system diagnosis showed battery issues, I learned that auxiliary batteries typically last 4-5 years before needing replacement. The symptoms were identical, error messages and a non-functioning car alarm system. The repair involved: Complete battery check of both main and auxiliary systems, Testing the charging circuit, Replacing the auxiliary battery, Resetting the alarm system Total cost was 330€ including parts and labor. The whole process took about 2 hours at the workshop. Since the replacement, all systems have been working perfectly. To provide more specific advice for your situation, could you share: Current battery age? Whether the main car battery has been replaced recently? Any other electrical issues youve noticed? If the error message appears consistently or intermittently? This information would help determine if youre dealing with a similar auxiliary battery issue or if theres something else going on with your electrical system.

Thanks for sharing your experience. My mileage is currently at 68910 KM, and I had my last service about 3 months ago. The car alarm started acting up shortly after the system showed a battery signal warning. The dealership told me both the auxiliary and main car battery are original from 2017, so Im thinking a battery replacement for both might be the best solution. Before I commit to the full replacement though, would it make sense to test the batteries separately first? The electrical issue seems to be getting worse, especially during cold starts.

The separate battery testing is definitely worth doing before a full replacement. In my Dodge RAM, the system diagnosis initially pointed to both batteries, but testing revealed only the auxiliary battery was the problem. A proper battery check costs around 50€ and can save money by identifying whether you truly need both batteries replaced. During my repair experience, the workshop did a load test on both batteries and found the main battery still had 85% capacity despite its age. Since your electrical issue is more noticeable during cold starts, this suggests a possible main battery problem along with the auxiliary battery alarm system fault. However, cold start problems can sometimes be misleading, in my case, what seemed like a main battery issue was actually the failing auxiliary battery interfering with the electrical system. Consider these steps based on my experience: Get both batteries tested separately, have the charging system checked, request a full system diagnosis to confirm no other electrical issues, if replacing both, consider having it done at the same time to save on labor costs. The total combined replacement would likely run around 500€, but individual testing might show you only need the auxiliary battery replaced, which would be closer to the 330€ I paid for my repair.

Thanks for the input. After reading your feedback, I decided to schedule a full battery check tomorrow. Given that both batteries are original from 2017 and the car alarm and battery signal warnings are getting worse, I think its time for a proper system diagnosis. The cold start issues are definitely concerning, but its smart to test before replacing both batteries. My plan is to: 1. Get the complete battery check done 2. Test the charging system 3. Based on results, either replace just the auxiliary battery or both 4. Have them reset the alarm system after the work. The 500€ estimate for both batteries seems reasonable if needed, though hopefully the electrical issue can be resolved with just the auxiliary battery replacement. Will update once I know the results of the system diagnosis and what exactly needs replacing. Really hoping to avoid any major electrical system problems beyond the batteries themselves.