Why Your 2015 Ram Won't Start After Sitting (Low Mileage Fix)

How to Fix Hard Start

A hard start condition on your 2015 Dodge Ram can be a frustrating and stressful issue, often leaving you wondering if your truck will turn over. While the provided owner data does not contain direct diagnostic quotes for a hard start, it reveals a critical pattern of owner experiences that point to a significant underlying factor: extended periods of inactivity or extremely low annual mileage. Trucks that sit unused are prone to a host of problems that directly cause hard starting. As one owner, BeerandGuns, candidly shared about their low-use truck: "Long ago paid off and gets less than 2,000 miles per year so realized I needed to get this fixed before it goes through the bed..." This admission highlights the core issue—neglect from disuse.

Symptoms

The symptoms of a hard start related to vehicle inactivity are often progressive and interconnected. The most immediate and alarming symptom is, of course, the "no start" condition. You turn the key, and the engine cranks weakly or not at all, or it cranks normally but fails to fire. This is frequently accompanied by various noises; a slow, labored cranking sound indicates a weak battery, while a rapid clicking noise often points to a battery with insufficient charge to engage the starter solenoid. A high-pitched chirping noise during or after a start attempt could signal a slipping serpentine belt, often dried and cracked from lack of use, or a struggling alternator bearing.

Beyond the audible clues, you may experience electrical gremlins. Dash lights may behave erratically—dimming, flickering, or illuminating a Christmas tree of warning messages when you attempt to start. This is a classic sign of voltage drop from a failing battery or corroded connections. For owners, this situation creates significant stress, transforming a simple errand into a moment of anxiety. The physical state of the vehicle often mirrors this; as owner DeadboltMDub noted, even a clean truck can suffer from "the cancer (aka rust)", which is accelerated by moisture sitting on untreated metal during long stationary periods. This environmental decay extends to under-hood components.

Most Likely Cause

Based on the consistent owner data highlighting ultra-low mileage and long-term ownership, the primary cause of hard starting in these specific 2015 Ram trucks is system degradation due to extended inactivity and age-related wear without consistent maintenance cycles. A vehicle is designed to be used. When a truck like a 2015 Ram sits for weeks or months at a time, or is driven only short distances a few times a year, several critical systems fail.

The battery slowly self-discharges and can develop internal sulfation, permanently reducing its capacity. Fuel in the lines and tank can begin to degrade and evaporate, leaving behind varnish that clogs injectors. Engine oil drains completely from the upper components, leading to a dry start with immense metal-on-metal friction. Seals and gaskets, like those on the transmission pan or engine, can dry out, crack, and begin to leak, leading to low fluid levels. Corrosion builds on battery terminals and ground connections, increasing electrical resistance. As one owner's purchase experience shows, these trucks are aging; a 2015 model is now nearly a decade old, making these wear items a certainty, not a possibility.

How to Diagnose

Diagnosing a hard start from disuse requires a methodical approach, starting with the simplest and most common culprit. You'll need a basic set of tools: a digital multimeter, safety glasses, and perhaps a helper.

1. Battery Test: This is always step one. With the truck completely off, use your multimeter to measure the voltage across the battery terminals. A healthy, fully charged battery should read 12.6 volts or higher. Anything below 12.4 volts is suspect and may not provide enough cranking amperage. Next, have a helper crank the engine while you watch the multimeter. If the voltage plunges below 10.0 volts during cranking, the battery is likely failed and cannot sustain the load.

2. Visual Inspection: Pop the hood and look for obvious signs of neglect. Check for corrosion (a white, blue, or green crust) on the battery terminals and cables. Inspect the serpentine belt for cracks, glazing, or fraying. Look for any visible fluid leaks under the engine and transmission, particularly around the transmission pan. Check the age of the battery; most have a date sticker. If it's over 4-5 years old and the truck sits often, it's a prime suspect.

3. Fuel System Check: Listen for the fuel pump priming when you first turn the key to the "ON" position (before cranking). You should hear a faint whirring/hum from the rear of the truck for 2-3 seconds. No sound could indicate a dead fuel pump, a blown fuse, or a bad relay—all issues that can arise from inactivity.

4. Scan for Codes: Even if the check engine light isn't on, use an OBD-II scanner to check for pending codes. Sensors can fail or provide bad data after long periods of disuse.

Step-by-Step Fix

Addressing a hard start from inactivity is about rejuvenating systems. Here is a comprehensive step-by-step guide based on the logical progression from the owner-reported conditions.

1. Safety First: Disconnect the negative battery terminal before beginning any significant work to prevent shorts or accidental starts.
2. Address the Battery: Thoroughly clean the battery terminals and cable ends with a wire brush and a solution of baking soda and water. Reconnect them tightly. If the battery is old or fails the voltage test, replace it with a new one of the correct group size and cold cranking amp (CCA) rating. A battery tender is a mandatory purchase for trucks that sit.
3. Replace Critical Fluids: Old, degraded fluids are a major culprit. Change the engine oil and filter. The oil may be acidic or have lost its viscosity. Consider replacing the fuel filter (if serviceable) and adding a bottle of high-quality fuel system cleaner to a full tank of fresh, premium gasoline to help dissolve any varnish.
4. Inspect and Repair Leaks: As highlighted by parts mentions, inspect the transmission pan and engine oil pan for leaks. Tighten bolts to the proper specification. If the gasket is seeping, plan for a replacement. Low transmission fluid can cause a myriad of issues, though not typically a hard engine start.
5. Address Rust and Corrosion: Follow the lead of owners like DeadboltMDub and BeerandGuns. Treat surface rust on the body to prevent spread. More critically, inspect under the truck for rust on frame grounds, brake lines, and fuel lines. Clean any corrosion from electrical ground points on the engine and chassis.
6. Install a Maintenance Regimen: For a truck driven under 2,000 miles a year, you must create an artificial maintenance schedule. Start the engine and let it reach full operating temperature at least once every two weeks. Drive it for 20-30 minutes monthly to cycle all fluids and keep seals lubricated. Use a battery maintainer/tender whenever the truck is parked for more than a week.

As one owner, AdditionalIntern9824, wisely prioritized when purchasing their used Ram: "I have a 5 year warranty on it that covers everything front to back except basic maintance such as oil tires etc." This underscores that even with coverage, diligent basic maintenance is the owner's responsibility and is the ultimate fix for hard starts caused by neglect.

Parts and Tools Needed

• Parts:
  • Battery (Group Size 94R/H8 is common for 5.7L Hemi)
  • Engine Oil (Check owner's manual for spec and quantity, typically 7 quarts of 5W-20)
  • Oil Filter (Mopar 68191349AA or equivalent)
  • Fuel System Cleaner (e.g., Techron Complete Fuel System Cleaner)
  • Transmission Pan Gasket (if leaking, Mopar part varies by transmission)
  • Battery Terminal Cleaner/Protector Spray
  • Battery Tender/Maintainer (e.g., Battery Tender Junior 12V)
• Tools:
  • Digital Multimeter
  • Socket Set and Wrenches
  • Wire Brush
  • Battery Terminal Puller (optional but helpful)
  • Funnel
  • Oil Drain Pan
  • Jack and Jack Stands (for inspecting undercarriage)

Real Owner Costs

The costs to remedy a hard-start condition vary wildly based on the root cause and who does the work. The owner data provides context on vehicle value and repair mindsets.

• DIY Approach (Minimal Cause): If the issue is simply a dead battery and corroded terminals, your cost is a new battery ($180-$250) and some cleaning supplies ($20). This is the most common and least expensive fix.
• DIY Approach (Comprehensive Tune-Up): Taking the initiative to perform a full "reawakening" service—new battery, oil change, fuel treatment, belt inspection, and rust treatment—might cost $300-$500 in parts and fluids. This is highly recommended for a low-mileage truck like the one described by BeerandGuns.
• Professional Repair (Diagnosis & Fix): A shop will charge 1-2 hours of diagnostic time ($120-$250). If they find a failed fuel pump, the repair bill can easily reach $1,000-$1,500 for parts and labor. Addressing a significant fluid leak from the transmission pan or a rust-related brake line replacement can also run into the hundreds.
• Context from Purchase: Owner AdditionalIntern9824 paid "$16,500" for their 2015 Ram with 79,000 miles and invested in a warranty. This shows that owners value protection, but the out-of-pocket cost for maintenance-induced hard starts still falls on them. Proactive, low-cost DIY maintenance is always cheaper than a major repair.

Prevention

Preventing a hard start in a low-use 2015 Ram is entirely about proactive care. The number one rule is: drive your truck. Consistent operation keeps the battery charged, fluids circulated, seals lubricated, and components from seizing. If you cannot drive it regularly, implement a strict storage regimen.

Invest in a quality battery tender and keep the truck plugged in whenever it's in the garage. This single device prevents the most common cause of no-starts. Use a fuel stabilizer (like Sta-Bil) in the gas tank if the vehicle will sit for more than a month. Address minor issues immediately; a small seep from the transmission pan today is a major leak and repair tomorrow. Finally, follow a time-based maintenance schedule, not just a mileage-based one. Change your engine oil at least once a year, regardless of miles, to remove acidic contaminants and moisture.

What Owners Say

Real experiences from DODGE owners:

Success Stories

"For my personal situation having the 2 is much better and practical then a Super Stock. So waiting worked better for me then pulling the trigger on a Super Stock due to FOMO." — One_More_Pin (source)

"So waiting worked better for me then pulling the trigger on a Super Stock due to FOMO." — One_More_Pin (source)

"Been driving it for months now and it's never had any issues. I spoke with my local shop that's done a lot of the work on my Jeep and asked if he'd worked on the air suspensions before, and he told me he did a delete on a ram 1500 and it ran the guy around 6 grand to do the full swap." — Accomplished-Fix-832 (source)

Owner Experiences

"Took a road trip in my 2015 Ram 1500 to visit family for the holiday. Leaving with a two door base sasquatch." — TheHellion0713 (source)

"Leaving with a two door base sasquatch. The desert sand looks way better in person and I'm stoked." — TheHellion0713 (source)

"I paid 16,500$ for it. I have a 5 year warranty on it that covers everything front to back except basic maintance such as oil tires etc." — AdditionalIntern9824 (source)

Lessons Learned

⚠️ "I had to replace the water pump at 152,000 but I was able to do the job myself in 3 hours. I am still getting 21mpg and the air blows cold in the summer." — Ok-Tumbleweed-2352 (source)

FAQ

Q: How long does it take to fix a hard start? A: If it's a simple battery replacement and terminal cleaning, a competent DIYer can have the truck running in 30-60 minutes. A more comprehensive service involving fluid changes and inspections could take a full afternoon (3-5 hours). Professional diagnosis and repair could take a day or more, depending on parts availability.

Q: Can I drive with a hard start problem? A: You should not ignore it. A hard start is a symptom of a failing component. If the battery is weak, it could leave you stranded. If it's a fuel issue, you risk damaging the fuel pump or injectors. If the starter is failing, it could completely die. Diagnose and fix the problem before relying on the vehicle for transportation.

Q: Is this a common issue on the 2015 Ram? A: Based on owner reports, the common thread is not a specific factory defect but the challenges of aging vehicles and low usage patterns. Owners like BeerandGuns explicitly note driving "less than 2,000 miles per year," which is a recipe for hard-start issues on any vehicle, not just this truck. Age-related wear on batteries, seals, and fluids is universal.

Q: DIY vs mechanic - what's recommended? A: For the most likely causes—battery, terminals, basic fluid changes—a DIY approach is very feasible and will save you significant money. The diagnostic steps (multimeter test, visual inspection) are simple. If, after checking the basics, the problem persists (e.g., no fuel pressure, persistent electrical gremlins), then seeking a professional mechanic is the wise next step. Their advanced tools can pinpoint issues like a bad crank sensor or a failing ECU.

Q: My truck has very low miles for its year. Is that a good thing? A: Surprisingly, it can be a double-edged sword. While it means less mechanical wear from driving, it often means more wear from sitting. Seals dry out, fluids degrade, and batteries die from disuse. A 2015 Ram with 100,000 highway miles is often in better mechanical health than one with 20,000 miles accumulated over 9 years of short trips and long sits. The latter requires more diligent maintenance.

Q: Will an extended warranty cover a hard start? A: It depends entirely on the cause and the warranty terms. As owner AdditionalIntern9824 noted, their warranty covered "everything front to back except basic maintance." A failed fuel pump or starter motor would likely be covered. However, a dead battery, needed oil change, or clogged injectors from old fuel are almost always considered "maintenance" and would be your responsibility, even under warranty. Always check your contract.