Our Hymer B544 PL, which is built on a Fiat Ducato chassis, has had a strange problem recently, the external temperature shown on the instrument panel has been erratic. Erratic in the sense that the temperature shown was 86°C, that tells you something is not right. I suspect the external temperature sensor.
Temperature showing —°C
When I collected the Hymer from its MOT a couple of weeks ago I noticed that the temperature had reverted to ‘normal’ so it was showing around 9°C, I thought that maybe something had been reset during the MOT, no such luck, by the time I arrived home, just 4 miles later, the temperature had climbed to an unseasonal 36°C.
Last week we did a week away in the Hymer, mid-March so temperature were either single figures or up to about 14°C, the temperature shown on the Hymer instrument panel was ridiculously high, but then it changed to —°C, just three dashes. This suggests to me that the external temperature sensor has failed. Not only that, but there appeared to be a problem with the cab heater too, we had to turn up the temperature to 32°C to get any warmth coming into the cab. That suggests that the two temperatures are linked in some way.
I am now researching the problem with the help of google and will update this post when more is known.
Keywords: Fiat Ducato external temperature sensor problem