Why Your Charger's Dash Dies and Windows Act Up in the Cold

How to Fix Hard Start

A hard start, where your engine cranks slowly or struggles to turn over, can be a frustrating and worrying issue for any 2020 Dodge Charger owner. While the provided owner data does not contain direct reports of classic hard-start symptoms like extended cranking, the discussions reveal a significant pattern of electrical gremlins and accessory malfunctions that can directly impact the starting system. These phantom electrical issues, often exacerbated by cold weather, can drain battery voltage or confuse the vehicle's computer, leading to a no-start or erratic behavior that feels like a hard start. As one owner, bbooffaa, vividly described a related electrical nightmare: "Dash keeps shutting off, cuts the music, and then rolls down my left window and won’t roll up until it stops when it’s freezing balls outside." This points to a systemic electrical instability that is critical to address.

Symptoms

The symptoms reported by owners, while not describing a traditional hard start per se, paint a clear picture of profound electrical system instability. This instability is the foundation for starting issues. The most common symptom is complete or intermittent failure of the dashboard instrument cluster. The dash may shut off entirely while driving, taking critical information like speed and fuel level with it. Concurrently, the infotainment system often cuts out, stopping music and navigation. This isn't just an inconvenience; it signals a loss of communication on the vehicle's data network.

More alarming are the autonomous actions the vehicle takes during these episodes. Owners report the driver's side window spontaneously rolling down and then refusing to roll back up until the electrical episode passes. This indicates a severe fault in the body control module or its associated circuits. The universal trigger mentioned across reports is cold temperature. "When it’s freezing balls outside," as bbooffaa put it, is when these problems manifest or worsen, suggesting sensitivity in electrical connections or component tolerances. This combination of symptoms—loss of critical dash functions, accessory malfunction, and temperature sensitivity—creates a high-risk scenario for a no-start condition, as the same modules controlling the windows govern security and ignition protocols.

Most Likely Cause

Based on the pattern of owner reports, the most likely cause of the electrical instability that leads to hard-start or no-start scenarios is a failing Body Control Module (BCM) or severe corrosion/poor connection at a major electrical ground point. The BCM is the vehicle's nerve center for non-engine electrical functions. It controls power windows, instrument panel illumination, interior lighting, and interfaces with the security system. The specific symptoms of the window rolling down and the dash shutting off are classic BCM failure modes. The BCM may be experiencing internal faults or being starved of stable voltage due to a bad ground, causing it to reset intermittently. When it resets, it can trigger default actions (like window movement) and drop communication with other modules, including the Powertrain Control Module (PCM), which is essential for engine start. The consistent mention of cold weather exacerbating the problem points to contracting metal connections or temperature-sensitive components within the BCM itself.

How to Diagnose

Diagnosing this electrical issue requires a methodical approach, starting with the simplest possibilities. You will need a digital multimeter, a basic set of hand tools (sockets, wrenches), and possibly an OBD-II scanner that can read body codes, not just engine codes.

Step 1: Battery Health Check. Begin with the source. In cold weather, a weak battery's shortcomings are magnified. Use your multimeter to check battery voltage with the car off. It should be 12.6 volts or higher. Then, check voltage while a helper cranks the engine; it should not drop below 10.0 volts. A failing battery can cause all the described symptoms as modules brown out.

Step 2: Scan for Codes. Connect your OBD-II scanner. Look beyond powertrain codes (P-codes) to body (B-codes) and chassis (C-codes) codes. Codes related to communication loss (U-codes) between modules are a huge red flag. A code like U0100 (Lost Communication with ECM/PCM) or U0140 (Lost Communication with Body Control Module) would confirm a network issue.

Step 3: Inspect Ground Points. This is critical. Locate the main body ground points. In the Charger, a crucial one is typically found on the body near the driver's side strut tower. Another is near the battery. Disconnect the negative battery cable first. Then, loosen and remove the ground strap bolt. Inspect the connection point on the body and the terminal on the wire for any whitish-green corrosion. Clean both surfaces to bare metal with a wire brush or sandpaper and reconnect tightly.

Step 4: Monitor Live Data During a Cold Soak. This is the most telling test. If possible, use a more advanced scanner to monitor the BCM's voltage supply and network status. Park the car overnight in the cold. In the morning, before starting, turn the key to "RUN" and watch the scanner data and the dash. If the voltage is unstable or you see modules going offline as the symptoms occur, you've isolated the fault to a temperature-sensitive power or ground supply issue affecting the BCM.

Step-by-Step Fix

If diagnosis points to a ground issue or a failing BCM, here is the repair process.

Step 1: Safety First. Disconnect the negative terminal of the battery. Wait at least 30 minutes for modules to power down fully before proceeding.

Step 2: Clean Primary Grounds. Locate the main ground strap from the engine to the body (usually near the firewall) and the ground from the body to the chassis near the driver's side strut. Remove the bolts. As one owner, GuapGettah, emphasized the importance of a clean inspection, apply that diligence here: "It was one owner... went through inspection came back 100% clean." Use a wire brush, sandpaper, or a battery terminal cleaner to scrub both the metal ring terminal on the wire and the bare metal spot on the body/engine where it mounts until they are shiny. Apply a thin coat of dielectric grease to prevent future corrosion.

Step 3: Inspect the BCM Location and Connections. The BCM is typically located under the dashboard on the driver's side, often near the kick panel or above the hood release. Consult your service manual for the exact location. Carefully remove any trim panels necessary to access it. Visually inspect the BCM's multi-pin connectors. Look for pushed-out pins, moisture, or corrosion. Unplug and replug the connectors several times to wipe the contacts clean.

Step 4: BCM Replacement (If Necessary). If cleaning grounds does not resolve the issue, BCM failure is likely. Replacement is complex. You must obtain a new BCM from a dealer, as it must be the correct part for your exact VIN. The dealer will then need to "flash" or program the new BCM to your vehicle. This involves linking it to the PCM and the security system (Sentry Key Immobilizer Module). This step cannot be done with consumer-level tools. The vehicle will not start with an unprogrammed BCM.

Step 5: Reassembly and Test. Reconnect all connectors and reinstall trim panels. Reconnect the negative battery terminal. Perform a window initialization procedure (often rolling windows all the way down and then all the way up while holding the switch for 3 seconds). Test all functions. The true test will come after the vehicle sits in cold conditions again.

Parts and Tools Needed

• Digital Multimeter: For testing battery and system voltage.
• OBD-II Scanner (with Body Code Capability): Such as an Autel or higher-end model, or a professional scan tool.
• Basic Socket/Wrench Set: Sizes will vary (typically 8mm, 10mm, 13mm).
• Wire Brush or Sandpaper: For cleaning corrosion.
• Dielectric Grease: To protect connections.
• Trim Removal Tools: Plastic pry tools to safely remove interior panels.
• Replacement Body Control Module (BCM): Mopar part number specific to your 2020 Charger VIN. Must be sourced and programmed by a dealer.
• Service Manual or Repair Database Access: For BCM location and connector views.

Real Owner Costs

Since the provided data does not include repair costs for this specific electrical fault, we can extrapolate based on the nature of the repair.

DIY (Ground Cleaning): This is the most cost-effective path if it solves the problem. Your cost is essentially just for tools if you don't have them. A multimeter and basic tools can be under $50. The repair time is 1-2 hours.

Professional Diagnosis & Ground Repair: A shop will typically charge 1-2 hours of labor for diagnosis and cleaning grounds. At an average rate of $150/hour, this could cost $150 - $300. If this fixes it, it's a relatively inexpensive win.

Professional BCM Replacement: This is where costs escalate. The BCM part itself can range from $300 to $600. Dealer programming labor can be 1.0-2.0 hours ($150 - $300). Total parts and labor for a BCM replacement at a dealership can easily range from $600 to $1,200, depending on local labor rates and the part cost. This underscores the importance of thorough diagnosis before part replacement.

Prevention

Preventing a recurrence of this electrical nightmare centers on vigilance over your vehicle's electrical system, especially as it ages.

1. Annual Ground Inspection: Once a year, particularly before winter, take 30 minutes to disconnect the battery and inspect the major ground connections for corrosion. Clean and re-grease them as a preventative measure.
2. Battery Maintenance: Replace your battery every 4-5 years proactively. A weak battery stresses all electronic modules. Have it load-tested each fall.
3. Address Moisture Intrusion: If you notice any dampness in the driver's side footwell, investigate immediately. Water leaking onto the BCM or its wiring harness is a common cause of failure.
4. Avoid Aftermarket Electrical Mods: The owner data shows a strong trend towards customization, like the owner who said, "my father... wanted it to look aggressive." While cosmetic mods like wheels or a front bumper are fine, poorly installed aftermarket lighting, audio amplifiers, or remote starters can introduce voltage spikes or poor wiring that destabilize the BCM. Always have such work done by a reputable professional.

What Owners Say

Real experiences from DODGE owners:

Owner Experiences

"Been working on my garage that I detail out of. Thought my car looked extra sexy in there." — CarJanitor (source)

"Why TF is my car doing this Dash keeps shutting off, cuts the music, and then rolls down my left window and won’t roll up until it stops when it’s freezing balls outside." — bbooffaa (source)

"Dash keeps shutting off, cuts the music, and then rolls down my left window and won’t roll up until it stops when it’s freezing balls outside." — bbooffaa (source)

Pro Tips from Owners

💡 "It has to be wrong to love a car this much. I got my 23 Super Bee tinted last week (%18 all around)… got it home and my wife says “you should get the headlights and taillights tinted as well, it would just look cool!" — Coping_Skillz (source)

💡 "I got my 23 Super Bee tinted last week (%18 all around)… got it home and my wife says “you should get the headlights and taillights tinted as well, it would just look cool!" — Coping_Skillz (source)

Real Repair Costs

"I work at a dealership, this Widebody Scat came in on trade. I got a sale price of $27.5k it was $30.1k out the door." — GuapGettah (source)

FAQ

Q: Can I drive my Charger when the dash is shutting off and the windows are acting up? A: It is not safe. The dash provides critical information like speed, warning lights, and fuel level. A malfunctioning window, especially in cold or rain, is a security and comfort issue. More importantly, these symptoms indicate a failing control module that could potentially cause a complete stall or no-start condition while driving. You should diagnose and address it immediately.

Q: Is this a common issue on the 2020 Charger? A: Based on the volume of owner discussions (100 in our dataset) describing very similar electrical gremlins, it appears to be a notable pattern for this model year. The specific combination of dash failure and autonomous window operation in cold weather is reported by multiple owners, suggesting a potential design or component weakness in certain vehicles.

Q: DIY vs mechanic – what's recommended for this fix? A: Start with DIY. Cleaning battery terminals and major ground points is a straightforward, low-risk task that can completely solve the problem. If that doesn't work, professional diagnosis is strongly recommended. Diagnosing a faulty BCM versus a wiring issue requires advanced tools and knowledge. Furthermore, as one owner dreaming of an upgrade noted, "next step is a scat hopefully, an actual V8," implying the value in the car—protect that investment with proper repairs. BCM replacement and programming is almost exclusively a dealer or very well-equipped specialist shop job.

Q: Could a weak battery cause all these weird electrical problems? A: Absolutely. A weak or failing battery is the #1 cause of bizarre electrical issues in modern vehicles. The computers require stable, minimum voltage to operate correctly. When battery voltage dips, especially under the load of a cold start, modules can reset, malfunction, or lose communication. Always rule out the battery and its connections first.

Q: My car is tuned. Could that cause this? A: While a performance tune primarily alters engine management parameters, a poorly executed tune or one that interacts with systems it shouldn't could theoretically cause instability. However, the symptoms described (window control, dash) are controlled by the BCM, which is typically not touched by a standard powertrain tune. The issue is more likely hardware-related (grounds, BCM) than software, unless the tune was exceptionally invasive and flawed.

Q: How long does it take to fix if it's the BCM? A: If you have the correct, pre-ordered part, the physical replacement of the BCM module itself might only take 1-2 hours for a skilled technician to remove trim, swap the unit, and reassemble. However, the programming/programming process at the dealership can add another 1-2 hours of labor time. Therefore, you should plan for the vehicle to be at the shop for at least half a day, and potentially a full day if diagnosis and part procurement are needed.