TECH HELP EDITOR
Q Why is the 12V TV socket not working in our motorhome?
I'm helping a good friend of mine who has lost power to the 12V TV socket in the cupboard of a Pilote P740 motorhome of 2018 vintage. I have looked at the back of the socket and there is a brown wire and a black wire.
I have traced these as far as I can go; the brown wire goes down into the bodywork by the door frame (presumably towards the main 12V power supply unit, which is under the offside passenger seat).
On this unit there is a fuse marked ‘television’ (in French). This 10A fuse has been checked, as well as all the other fuses. I cannot find a reason why there is no power to the TV socket.
Any assistance is appreciated or can you recommend an auto electrician that specialises in motorhomes in the Bedfordshire area?
Colin Snow
A There is a need here to use a multimeter to measure some voltage. I would start at the Schaudt 12V electrical unit and the fuses.
With the multimeter set to DC volts, connect the meter's black lead to the base vehicle chassis or battery negative. Use a crocodile clip, as you need to leave this meter negative probe connected to battery negative for all the tests I am going to suggest you do.
Test 1: Put the meter's red lead on the TV fuse end 1 and check for 12 volts.
Test 2: Put the red lead on the TV fuse end 2 and check for 12 volts. If these two tests are OK then extend the red meter lead so you can access the 12V TV socket.
Test 3: Connect the meter's red lead to the TV socket's brown wire and check the voltage. Note this voltage. Is it 0V or 12V?
Test 4: Connect the meter's red lead to the TV socket's black wire and check the voltage. Note if this voltage is 0V or 12V.
If you find 12V on tests three and four, then most likely you have a break in the negative wiring to the TV socket.
Have you assumed that the brown wire was live and the problem is that the polarity at the socket is not what you expected? Quite often on continental vehicles the brown wire is chassis/battery negative, and the black wire is live.
Any competent vehicle electrician will be able
