TECH HELP EDITOR
Base vehicle expert
Q What is causing my motorhome's indicator warning light to appear?
My 'van is a 2016 Chausson 610 Welcome built on the Ducato with extended mirrors. A while ago a dashboard warning come up showing ‘check RS indicator’ with the usual orange triangle.
I changed both front indicator bulbs, but that didn't cure the problem. I then went on to change the mirror-mounted ones, but unfortunately the wattage was not visible on the old bulbs.
The handbook says that they could be 5W or 16W, so I tried 16 first but no cure. Externally, everything flashes at the correct rate, including the Jokon LED rear ones.
My local garage advised trying 21W bulbs; with these the warnings asked me to check both left and right sides, but then cancels after two or three left and right turns and things return to normal.
At all attempts the indicators all flash at the correct rate. Your help would be very much appreciated.
Steve Bovey
A The change to 16W bulbs happened in around 2011, so your 2016 X290 must have these. They are easily identifiable because they are quite big compared to the 5W models. The lenses are clear-ish and the bulbs should be orange in colour. Both sides need to have the same bulbs fitted for everything to work correctly. The vehicle body computer does a check of the total electrical load every so often and will know if something is not right.
Once all of this is checked and correct, if you still have any issues, the wiring loom needs to be checked at the flexi where the door is attached. There are sometimes issues with a connector below the window switches. It's very awkward to get to, but this only normally rears its head if the mirror has been changed.
In some rare circumstances, the body computer (CAN bus) that controls lighting functions can get confused by the chopping and changing, particularly if you have lamps of a non-standard specification elsewhere on the vehicle. A reset to the original settings may be necessary and this is known as proxi alignment.
Most full-featured diagnostic units that access the CAN bus can perform this procedure, and it only takes a few minutes. All of the connected nodes of the system are scanned for their identity, status and operation before the factory settings are restored. Devices that have had their settings learned by the ECU over time will have to educate the body computer again, but this only takes a few miles of being driven.
I'll remind owners to get a further check carried out while they have access to a Fiat-compatible diagnostic unit. Ask the operator to connect to the engine ECU and perform a test on the cooling fans. These actuator tests only take a few seconds to perform. There may be as many as three different ‘speeds’ to check, but all are necessary.
Some vehicles with no air-con may only have one fan that operates at two different speeds (high and low). The fans have a tendency to fail,
