“Aux Switches Temporarily Unavailable Battery Charging.” is a concerning error message pop up on your dashboard display if you drive a Jeep Wrangler or another Jeep model with a dual battery setup.
Don’t panic! This common error is usually easy to resolve once you understand what causes it.
The “Aux Switches Temporarily Unavailable Battery Charging” error indicates low voltage in the Jeep’s dual battery system, likely from a discharged or failing main or auxiliary battery. Driving the Jeep or charging the batteries can temporarily resolve it, but replacing weak batteries that fail testing is the permanent fix to restore normal electrical operation.
However, there could be many other reason that causes this issue.
So, we’ll explore what triggers it, and how to get your Jeep back up and running. Our goal is to provide troubleshooting tips to help identify and fix the underlying issue.
Aux Switches Temporarily Unavailable Battery Charging Error. What Does it Mean?
In Jeeps with dual batteries, there is a main starter battery that powers the engine, and an auxiliary battery that runs accessories like lights, winches, and onboard power outlets. The two batteries work together to ensure sufficient electrical power no matter where you take your Jeep off-roading.
The “Aux Switches Temporarily Unavailable Battery Charging” error simply indicates that your Jeep’s computer has detected low voltage or an abnormal reading from the dual battery system. this can also lead to issues with your Stop/Start System.
As a failsafe, it immediately cuts power from going to any auxiliary switches and accessories running off the second battery via Uconnect system. This prevents draining the starter battery which could leave you stranded.
In most cases, this error points to an underlying issue with the auxiliary battery itself, the alternator not charging correctly, or another electrical gremlin that needs diagnosis. Consider it a warning light that something needs attention to restore optimal operation of your Jeep’s charging and power systems.
Reasons for the Error Message
There are several common culprits responsible for triggering the “Aux Switches Temporarily Unavailable Battery Charging” error message in your Jeep:
Failing or Old Auxiliary Battery (Most Common)
The most likely root cause of this error is a degraded auxiliary battery that can no longer hold a full charge and maintain proper voltage levels.
As batteries naturally age and corrode internally, their capacity and ability to store energy diminishes over time. Extreme hot or cold operating temperatures can accelerate this degradation.
Leaving your Jeep sitting unused for weeks or months also allows batteries to slowly discharge over time, taking them out of their optimal voltage range. An old weak battery will struggle to provide sufficient power to your Jeep’s electrical accessories and trigger the computer to cut off the aux switches as a precaution.
Faulty Alternator
Your alternator is responsible for charging both the main starter battery and auxiliary battery while driving. If it has bad diodes or internal faults, this prevents it from properly charging the dual battery system.
Insufficient charging allows voltage levels to drop. An alternator that is not outputting its designed amperage cannot overcome drain on the electrical system. Having your alternator tested or replacing it with an upgraded high-output alternator can improve charging performance.
Dead Battery/Insufficient Charge
A completely dead auxiliary battery that has sulfated from sitting at zero charge for an extended time will certainly cause issues.
But even just a partially insufficient charge from low recent driving time, a parasitic draw overnight, or other charging system malfunction can leave the auxiliary battery under 12.5 volts and trigger the error message. The battery needs to be regularly recharged to its maximum capacity to operate properly.
Electrical System Issues
Various electrical problems can lead to the “Aux Switches Temporarily Unavailable Battery Charging” error by interrupting the charging system. Loose battery cable connections that have corroded or vibrated loose over time cause impedance and voltage drop.
Inspect connections at the battery terminals, chassis ground, and between starter/auxiliary batteries for tightness. Also check high-amp fuses connected to the auxiliary battery and the fuse/relay array that controls switch power. If a fuse is blown or relay defective, it disrupts electrical flow. Replacing bad fuses or relays restores normal operation.
Cold Weather Conditions
Extreme cold temperatures can cause batteries to discharge faster and reduce cranking power. The thickened oil makes it harder for the engine to turn over, pulling more amps. Batteries also have reduced output when cold. This greater strain makes electrical issues more likely in icy conditions. Store your Jeep in a garage if possible.
Infrequent Driving
Letting your Jeep sit unused for weeks at a time allows the batteries to gradually self-discharge. Lack of regular engine running and alternator output fails to keep both batteries topped off at peak voltage. Run your Jeep or take it for drives periodically to charge the system if not daily driving it.
Parasitic Draw From Accessories
If a switched accessory like lights, winch or onboard electronics is shorted or malfunctioning it can slowly drain the auxiliary battery over time. Use a multimeter to measure parasitic current draw with all switches off. If above 50-100mA, a faulty component may be present. Disconnect accessories one by one to isolate the source.
Identifying the specific issue draining or preventing proper charging of your auxiliary battery is key to permanently resolving the error message. Consider when the message started occurring and any changes or events preceding it to help pinpoint the root cause. With some basic troubleshooting, you can zero in on the offending component and get your Jeep’s electrical system back on track.
Solutions to Fix “Aux Switches Temporarily Unavailable Battery Charging” Error
If you see the “Aux Switches Temporarily Unavailable Battery Charging” warning pop up, don’t despair. There are a number of DIY troubleshooting tips you can try to get your Jeep back up and running:
Drive Extended Time to Recharge Battery
Simply driving your Jeep for 30-60+ minutes will often allow the alternator to recharge both the starter and auxiliary batteries back to full capacity and make the error message disappear. This restores normal voltage levels and works best if the issue was just a partially depleted battery.
Use Smart Battery Charger Overnight
Connecting an automatic smart battery charger to your battery system overnight can safely bring both batteries back up to a full state of charge if either was drained. Choose a charger with an automatic shutoff feature to prevent overcharging.
Load Test Batteries and Replace if Failing
Use a battery load tester or have your local auto parts store test your starter and auxiliary batteries under load to diagnose if one or both can no longer hold a proper charge and need replacement.
Inspect Alternator and Repair/replace if Faulty
If battery testing checks out okay, have your alternator inspected for proper charging operation and output. Check connections for corrosion and have the alternator repaired or replaced if found to be malfunctioning.
Verify Fuses
Closely inspect the high capacity fuses connected to the auxiliary battery circuits. Also check the fuse and relay array that controls power to the auxiliary switches. If any fuses are visibly blown, replace them with identical new fuses to restore normal operation. Never use a higher rated fuse for a circuit.
Check Battery Cables and Terminal Connections
Carefully inspect the heavy gauge battery cables that connect your starter and auxiliary batteries together as well as to the vehicle chassis. Look for corrosion buildup on the terminals and ensure connections are tight. Loose connections cause impedance that reduces voltage. Clean any corrosion and tighten terminals to specification.
Inspect Fuses and Relays
Check all fuses and relays associated with charging and the auxiliary electrical circuits. Look for any that are blown or defective and replace them. Key locations are the Power Distribution Center under the hood and the TIPM (Totally Integrated Power Module) inside the cabin. Refer to a wiring diagram to ensure critical relays are functioning properly.
Check Accessories for Parasitic Draw
Use a multimeter to measure current draw on your battery system with all accessories and switches turned off. Draw should be less than 50mA. If current is higher, a shorted component could be draining your battery. Remove fuses one by one to isolate the problem circuit.
Use Trickle Charger
For Jeeps that sit for weeks during winter storage, connect a high-quality automatic trickle charger to maintain the batteries at 100% charge. Choose a charger with temperature compensation and a desulfation mode to condition the batteries.
Consider Upgrading to Genesis Dual Battery Setup
For avid off-roaders, upgrading to an AGM auxiliary battery or lithium battery pack can provide higher sustained power for winches, lights and accessories when off-grid. The Genesis dual battery kit provides 200A of power from LiFePO4 batteries.
Checking critical electrical connections and components will help get to the bottom of charging issues and eliminate the frustrating “Aux Switches Temporarily Unavailable” warning.
Signs Your Batteries Are Failing
Watch for these common indicators that your auxiliary battery is on its way out:
- Slow engine cranking when starting
- Headlights or dashboard lights dimming or flickering
- Inability to hold a full charge for normal duration
Catching battery issues early allows for proactive replacement before getting stranded with a dead battery.
Maintaining Optimal Battery Charge
- Use a smart charger periodically in battery maintainer mode to keep your auxiliary battery properly conditioned when in storage.
- Install a Jeep-specific battery tender that automatically floats and maintains battery charge when parked.
- Ensure your Jeep’s intelligent battery sensor is working properly to provide accurate voltage readings to the computer.
Conclusion
In summary, the “Aux Switches Temporarily Unavailable Battery Charging” message is your Jeep’s way of telling you it detects an abnormal electrical charging condition that needs your attention.
With some basic troubleshooting like battery testing and electrical inspections, you can identify and resolve the underlying issue and get back to the fun of Jeep ownership! Proper battery maintenance is key for avoiding nagging electrical gremlins.
