Diamond Dave

See other Advice articles filed in ‘Electrics’ written by Diamond Dave
Remapping your motorhome can improve the performance and mpg – but it's certainly not a DIY job, says Practical Motorhome's workshop guru Diamond Dave

I often hear people bemoaning the modern electronic systems in vehicles, usually accompanied by reminiscences of temporary fan belts made out of girlfriends’ tights. My stock answer has always been, “I remember those days and the roadside fixes, but did it really have to occur so often?”. In one month recently we had a couple of jobs in that were so complicated that it almost made me wish for points and condensers again. Almost!

We also had a project ’van in: a conversion that had gone terribly wrong. It represents a cautionary tale: the owners trusted the conversion to a company that has since liquidated. When the van arrived at our workshop it was in a sorry state.

Incomplete remapping is costly to fix

The first job this monthwas a ’59 plate Ford Transit Connect for a commercial customer. We had it booked in for a service but on the appointed day the regular driver phoned to say it would be late and arriving on the back of a recovery truck.

The driver explained it had been going fine but a warning light had been on the dash for a week or two, then this morning the instruments just died. It did restart and the instruments came back to life but the battery was hot and reading over 15 volts with the engine running.

We don’t do much with diagnostics, only having the basics available, but a neighbouring business specialises in vehicle electronics so after carrying out the service I sent it round. The technician from the specialist was baffled. This vehicle was showing some very odd faults and missing data along with communication issues to several of the on-board ECUs.

Further probing revealed it had been remapped but not very well. On the Connect, the main ECU takes signals from a variety of sensors, including wheel speed, but also needs basic parameters in memory, items such as wheel size/tyre diameter and final drive ratio, but all these were missing. We opted for a back-to-standard remap and re-input the required figures but they wouldn’t save. Totally baffled, the tech spent a day on it before discovering the problem. During the remapping procedure the VIN needs to be typed in and whoever had done it had missed one digit out. Eight hours and more than £400 later it now runs like a charm with no warning lights.

The battery overcharging was also down to the remap. On the Connect, alternator output is regulated through the engine ECU so with all the other issues going on it just didn’t want to play.

Airbag ECU fault

The second job was a 2011 Peugeot Boxer-based ’van that failed its MOT because the airbag warning light was on. Another call to our local electronics wizards and it turned out the airbag ECU had failed. We proved this by swapping it with another identical vehicle and the fault transferred with the ECU. Again the final bill was north of £400 for a diagnosis followed by a new ECU and programming but all is now healthy. Well, except for the owner’s bank balance.

Why did the ECU fail? We don’t know. It could be anything from moisture getting into it to just a dry soldered joint inside but things do fail sometimes.

Poor van conversion rescue

We also have a project van conversion that has gone wrong. A couple downsizing from an S-Class Hymer opted for a bespoke conversion on a three-year-old Citroën Relay LWB. They chose a converter who found them a van and said all the right things; deal done and conversion started. Then the converter went into liquidation during the job. If only they'd just bought a motorhome from one of the National Caravan Council's approved motorhome dealerships or chosen one of the dealers voted for each year by fellow motorcaravanners in Practical Motorhome's Owner Satisfaction Awards.

We agreed to complete the conversion but when the van was delivered to us it was in a sorry state with no cab seats, bases, or door mirrors and 0.8 volts in the battery. The bodywork had picked up several dents and scratches and the conversion work was all awry. Neither the window apertures nor the toilet door hatch had been cut. The fridge was in the wrong position and almost no insulation had been installed even though the washroom, kitchen and seating area, along with the ceiling, were all fitted.

Job one was to strip out almost everything. The only acceptable bit was the rear storage area and wardrobe. The floor had a spongy section, so up came the vinyl covering followed by the forward section of plywood floor. We were all shocked to find that the converter had put new plywood down over the original plywood floor covering, which was rotten in several places. We removed the rotten underfloor only to find the steel floor quite battered, and covered in what appears to be congealed animal fat! So it has been degreased, straightened out as much as possible, primed and coated with rubberised stonechip paint to give an impervious barrier layer.

After that I cut in the window apertures, toilet door aperture and one for a ‘crystal turbo vent’ in the washroom roof. Then it spent two weeks in a local bodyshop having all the damage sorted out. Finally we could start to transform the vehicle into the motorhome the clients wanted all along.

Running a motorhome workshop is never dull!

For more tips on running your motorhome, check the advice in the latest issue of Practical Motorhome magazine.

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