Wanderer Motorhome Page 37

Driving in France?
Then this web site is a must:

email Brian,

Environmentally Safe Toilet Treatment for motorhomes, caravans and boats:

For a Holiday with a difference in a Motorhome, see this link:

Great Ormond Street Hospital
Children's Charity 
Great Ormond Street Hospital, Children's Charity, 40 Bernard Street, London.  WC1N 1LE
Tel: 020 7239 3000 
Click on the link to donate

As author and maintainer of this web site. I do not save, retain, or sell  any email addresses of those who email me. Should you not get a reply from me, please send again, I might have missed it in my spam catcher!

Additions to Motorhome pages:-
1.Fitting New Automatic Water System Pump
2.Winterising the water pump.
3.Water Tank Level Meter-modification to electronic circuit

4.Basin Mixer Taps - tip & how to repair a dripping tap.
5.Extending Fresh Water Drain Tap to Outside

To Speed up page loading, images are shown as a 'Thumbnail.' Clicking on these will show the complete image

To home page







































Our MH has now been sold so this web site will not be updated again

[click above for pictures]

Due to my age, 80 years old, and health reasons we are forced to give up the pleasures of a motorhome,  and has now been sold.

Description of the motorhome can be seen through out the pages of my web site here.

The MH has MOT until MAR 2017 and its mileage is 109224


1. LED Reading lamps in the Motorhome   2. A modification circuit to run 48 LED lamps 3. MR16X48 LED Lamps


Having used these devices in our Motorhome, I recommend caution in their use. This is due to the varying voltages as seen in a Motorhome. Those from the leisure battery charger, Leisure battery and the alternator. All could produce a voltage greater or equal to 14.5volts, which will cause a failure to the lamps specified at a maximum 12.4 volts operation. Mine failed after 20 hours.The exercise below is left for information only.

Anyone wanting to know who the LED lamp supplier was who would not exchange these lamps, email me!


I have since removed these devices and fitted MR11 lamps with 48LEDs into the same enclosers making them far superior to the old ones.

See: NEW lamps and Modified circuit to run LED lamps


The LED introduced to replace, the filament lamp         LED lamp size compared to a GB pound coin

     Last summer reading in our Motorhome after dark was a problem. After 2 hours, the lights dimmed. This was due to the current taken by the lamps. Each one took one Amp, three lights and the overhead fluorescent was about 4 amps. This created a one volt drop on the battery. Not much! But it produced a change in florescent glow from the bulbs and just enough irritation to complain. It's no problem when on a site with hookup, and the battery charger switched on, but when no hookup is available, a one volt drop makes a marked different of the lamp luminance.  A solution had to be found! A new battery perhaps, or a change of lamps for the new LEDs' to reduce the current taken.

     After noting recent trends about Light Emitting Diode [LED] lamps, including reading articles, and one from John Wickersham, regarding the increased light efficiency of the newer types. I did some research on changing the filament lamps to LEDs' also the suitability in my Motorhome.

     I ordered 3 X 15mm diameter bayonet fitting, 24 White LEDs' custom enhanced. The enhanced I assumed was due to 6 LED's which are fitted at the Rear! this eliminates a dark patch at the rear of the reflector as well as enhancing the 18 LED's at the front. When ordering, it is advised that lamps which are constructed with voltage stabilisers are used, as they are prone to failure if over voltages are present even for a short time.

     They arrived overnight and fitted into my reading lights, except the 'Bulb' was lightly larger than the original so would not push into place. The reflector had an aperture similar to the old filament lamp.

LED & Filament

LED & Filament compared

      I am one of those people who find it a chore to have to send things 'back' so shrugged my shoulders and thought; 'Another bad buy.'

     With time on my hands I wondered if there was a solution to the problem. New reflectors perhaps, the new ones might have similar problems! Plus the cost at £18 each.

     I stripped the lamp bracket down to find the bulb of the lamp was fouling the reflector which was holding off the base Bayonet fitting. See my pictures below for the solution to the problem.

     The solution was to shorten the lamp body which then enables the lamp to make voltage contact with the positive terminal and to be secured by the bayonet fitting.

All pictures can be enlarged:-

Here is seen the two reflectors on the bench, the left is waiting for the modification. The right hand one has been started, the negative tag retainer is being prised off to allow the bayonet fitting, which it secures,  to be released for modification

LED Reflector tag being taken off, to enable the bayonet body to be taken out, for modifications.

LED Reflector negative terminal tag has been taken off the outer body to enable modifications to lamp inner body. Note the negative supply is coloured WHITE




Here the LED lamp inside the barrel, of the reflector container, not being able to clip into bulb bayonet fitting. Barely going in half way.



Here the LED superimposed on the Bayonet body showing the constraint of the lamp holder. The shoulder of the reflector was holding the shoulder of the lamp and stopping the barrel of the LED from being pushed into the bayonet locking.


The body has been cut to allow an overall shortening of the lamp body,
and enable the LED lamp to reach the Voltage supply contact.







I did not have the correct tool so this was my method of enlarging aperture.
this will allow the reflector to fit over the bayonet portion of the lamp body.
the pliers was pushed into the body and rotated at the same time.

A close up of the reflector aperture and my method of opening it up, using the pliers.


Here the cut lamp body has been fitted over bayonet fitting.
The LED lamp is now held inside the bayonet retainer.
If the reflector is too loose, after the modification, there is enough
room to Pop Rivet the body walls together.

This is a view of the lamp entry aperture. The cut bayonet body
can be seen level withe reflector base.

This shows the rear of reflector container which secures the lamp body.
As the LED lamp body has been shortened, the reflector body has to be squeezed
 in gently to meet the LED Lamp body to enable them to be secured together
 with the centre holed securing crimp.


Above can be seen the reflector after the modification. 
Note: The black wire is the positive feed, if connected to the Negative Supply volts, the LED lamp will not work.


Here is seen the LED lamp now fitted in place. This comprises of 24 LEDs' with
18 showing,  6 are at the side of the lamp to give additional reflection off the reflector.

An image of the Filament lamp

An image of the Filament lamp

An image of the LED lamp

Having fitted these lamps into our Motorhome in the December, our first major use was in May the following year, 2007.
After a total of 20 hours use in the South of France two failed. 3 LED on one and 12 failed on another.
This was the reply I received from the supplier after an email to them explaining my problem:


                           We offer 90 day warranty on these bulbs, for them to fail this early you have
supplied well over the 14.5 volts required.

My concerns expressed in later emails have been ignored!


Modified circuit to run 3 X 48 LED Lamps

I have since, again, modified the lamp holders and fitted 48 LED lamps, MR11 types. 

To ensure they don't fail again I fitted a 10 to 15 volt to 12volt stabiliser. This circuit can be seen below. It came from a Radio Amateur magazine, which was designed for charging batteries. I converted the design to give 12volts output whatever the input voltage was. The reason being the Leisure battery will give quite a lot of current even when it has discharged below normal. Just what is needed for wild camping.

So I found I could get 12volts out at 10 volts in. Or, at 15 volts in I could get 12volts out. The maximum current I found for this design was 1Amp. It will supply the 3 X 48 LED lamps with no problems.  The circuit was built from parts in my junk box. Improved quality and high gain components would probably give more current.

You can buy a similar function power supply, source the internet, for £49.99

I ran the circuit for a number of hours at maximum current and was pleased to find the components did not get hot. I did place the Transistors on a heat shield.

The device was fitted in series with the cables which fed the lamps. Isolating the Lamps from the Motorhome 12 volt electrics.

 You will note I am not giving step by step instructions on how to build and fit, as this modification should only be done by a qualified person<person>

I have used my constructed device for two years and it has been reliable in use.


MR16 48 3528 SMD LED Bulb<MR16 LED>

I have since sourced and fitted, from EBAY-Hong Kong, May 2011: 

MR16 48 3528 SMD LED Bulb Lamp Light Warm White 12V 9W

That's 48 LEDs' in its body.

The circuit below can be integrated using modern components with a higher current rating.

The circuit below will give 1Amp, this I have found will drive the 3 X 48 LED lamps which take 170Milliamps each, about 1/2 an amp. total<total>

The lamps are so bright, that it is not advised to look at them directly!


Also see the link below for ideas on uptodate modern circuits: 
http://www.siongboon.com/projects/2005-08-07_lm2576_dc-dc_converter/#Resistor parallel table

Click for larger images

48 LED Lamp

48 LED Lamp

48 LED Lamp

48 LED Lamp


48 LED Lamp

48 LED Lamp


To Page Links & Site Index

To home page