Auto-Sleepers Electrical System
(Ford Transit Custom Air, 2023 Model Year)
View official manual on manufacturer's site ↗Also Fitted To This Caravan
Master Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Possible Cause | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|---|
N/A | The 12V socket outlet has no power reaching it. | Fuse blown | Track down the fault and fit a replacement fuse of the identical rating. | DIY Safe |
Recommended partsAffiliate linksView 2 optionsHideCheck whether the blown fuse is a standard or a mini blade fuse (mini ones are roughly half the size), then choose the matching kit: This fault doesn't say which fuse rating has blown, only to replace it like-for-like. Both kits cover the common ratings (5A-30A) - match the rating printed on the blown fuse. Standard blade fusesCar Fuse Kit - 60pc Assorted Blade Fuses (5A-30A) with Storage Case and Fuse Puller~£5.994.5★ (1,500+ ratings), sold by KANGRUI, dispatched by Amazon - includes 15A blade fuses plus a puller and storage case View on Amazon →Mini blade fusesNilight 120pc Mini Blade Fuse Assortment (5A-30A, ATM/APM) with Fuse Puller~£5.244.5★ (2,500+ ratings), sold by Amazon - includes 15A mini blade fuses View on Amazon → | ||||
N/A | Habitation 12V does not operate | Vehicle ignition “on” | Switch “off” ignition | DIY Safe |
N/A | The battery won't hold its charge. | Current being drawn | Make sure every appliance is switched off whenever it isn't in use. | DIY Safe |
N/A | The control panel's display is garbled or behaving erratically. | Follow the control panel's own handling guidance - the software running it may have crashed. | To reboot the control panel: turn off the EC328PSU's own charger and take out fuses 1 and 2 there - both 2x20A, one feeding the leisure battery, the other the vehicle battery - leave them out for around half a minute, refit them, then power the charger up again. As an alternative approach, prise the control panel's bezel free by pulling its bottom centre downward, unplug the multi-way connector, pause for roughly half a minute, then reconnect it and put the bezel back together. | DIY Safe |
N/A | The battery discharges quickly while appliances are running. | Battery not fully charged | Fully recharge battery | DIY Safe |
N/A | 230V system inoperative | RCD/MCB switches tripped out | Reset circuit breakers | DIY Safe |
N/A | RCD/MCB keeps tripping out | An appliance is drawing more current than the circuit allows. | Only 10A is available on this circuit. Consult your dealer. | Professional Intervention Required |
N/A | The reverse polarity light on the PSU is lit. | Generator being used | Seeing the reverse polarity light while running a generator is a normal quirk with certain generator types. Rather than earthing the neutral conductor directly, some generators centre-tap the earth connection instead, which leaves both the neutral and live conductors sitting around 110V above earth - and that 110V difference is what lights the neon polarity indicator.
It's usually still safe to keep using the generator, but check its own handbook for confirmation. | DIY Safe |
N/A | Control Panel current reading incorrect | — | To recalibrate the current sensor: turn the charger switch off and the control panel power off too (no LEDs lit), then use the down/left arrow to scroll the display to the battery current reading. Press and hold the select (left arrow) button until 'calibrating...' appears, and keep holding until the current reading comes back, then release.
The reading should now be accurate. | DIY Safe |
N/A | The PSU is giving no 12V output. | Other fault | Contact your Dealer | Professional Intervention Required |
N/A | Habitation battery not charging | Contacts dirty/loose on battery terminals | Clean and check for tightness | DIY Safe |
N/A | EC328PSU case becomes hot under heavy loads | Heavy loads causing high operation temperatures | Always keep the ventilation slots free for airflow, and never rest combustible materials against or next to the EC328PSU. If it overheats the PSU will shut down, restarting automatically once it's cooled. | DIY Safe |
N/A | One or more 12V appliances have no power reaching them. | Circuit fuse blown | Track down the fault and fit a replacement fuse of the identical rating. | DIY Safe |
Recommended partsAffiliate linksView 2 optionsHideCheck whether the blown fuse is a standard or a mini blade fuse (mini ones are roughly half the size), then choose the matching kit: This fault doesn't say which fuse rating has blown, only to replace it like-for-like. Both kits cover the common ratings (5A-30A) - match the rating printed on the blown fuse. Standard blade fusesCar Fuse Kit - 60pc Assorted Blade Fuses (5A-30A) with Storage Case and Fuse Puller~£5.994.5★ (1,500+ ratings), sold by KANGRUI, dispatched by Amazon - includes 15A blade fuses plus a puller and storage case View on Amazon →Mini blade fusesNilight 120pc Mini Blade Fuse Assortment (5A-30A, ATM/APM) with Fuse Puller~£5.244.5★ (2,500+ ratings), sold by Amazon - includes 15A mini blade fuses View on Amazon → | ||||
N/A | The PSU is giving no 230V output. | Other fault | Contact your Dealer | Professional Intervention Required |
N/A | Control Panel contrast poor | Observe control panel handling instructions. | Take the control panel off as described above, but leave it plugged in. Use a small jeweller's screwdriver to carefully adjust the contrast preset on the back of the panel. | DIY Safe |
N/A | Control Panel has no display | — | Check the batteries, switch the EC328PSU charger on, and confirm the mains supply is connected. Check the control panel's connecting lead at both the EC328PSU and behind the control panel itself. If that doesn't resolve it, contact your dealer. | DIY Check / Tech Fallback |
N/A | The PSU is giving no 230V output. | The lead linking the site supply to the vehicle isn't plugged in | Check the lead is connected properly - also check the socket where it plugs into the underside of the PSU. | DIY Safe |
N/A | The PSU is giving no 230V output. | RCD switched off | Reset the RCD. | DIY Safe |
N/A | The PSU is giving no 230V output. | RCD not operating correctly | Check the supply polarity; if the RCD keeps failing, contact your dealer, as there's likely an equipment or wiring fault. | DIY Check / Tech Fallback |
N/A | The PSU is giving no 230V output. | MCB switched off | Reset the MCB by switching it off (down) then back on (up); if it keeps tripping, contact your dealer, as there's likely an equipment or wiring fault. | DIY Check / Tech Fallback |
N/A | The PSU is giving no 230V output. | No or deficient supply from the site | Contact the site warden for assistance. | Professional Intervention Required |
N/A | The reverse polarity light on the PSU is lit. | Mains supply reversed | This light is designed to catch a reversed/crossed live and neutral supply on UK-wired sites - if it comes on, suspect a fault with the site's own supply, or its connecting cable. Outside the UK it can light up with no actual fault present, so check with the site warden in that case. | DIY Check / Tech Fallback |
N/A | 12V power switches itself off | — | This is usually the battery-save feature stepping in to protect the vehicle and/or leisure battery, or the engine having been started (in which case equipment gets disconnected automatically to meet EMC requirements). | DIY Safe |
Frequently Asked Questions
Q: What should I do if the low battery alarm goes off?
Plug the vehicle into a 230V mains supply to top up the leisure battery.
Q: What should I do if the low battery alert is triggered on a lithium battery?
Recharge it - either using the onboard charger, or by running the engine.