Hi,

I have a 2000 2.8 DTD Motorhome and wondered if anyone could shine a light (no pun intended) on this issue ?

When I put the main beam on my dipped headlights go out it has always done that and I didn't think anything was wrong ? But just been told and confirmed by my mate who has same van that all 4 of the 90mm lights should be on. So wonder if anyone can give me some pointers as to what is wrong and how to fix this problem ?

I have swapped the 2 relays, but that hasn't helped.

Thanks

I cannot give a definitive answer, however my curiosity was aroused.

My vehicle is an x244 2.8JTD, and eLearn diagrams suggest that the dipped beams do not stay on when main beams are selected. This is contrary to what the descriptive text in eLearn says, and to what happens in practice. Errors and discrepancies in eLearn are not unusual.


It may be that Tranby's and his mate's vehicle were built at slightly different times, or specifications.


For my later vehicle eLearn shows a "switch control unit" in the wiring route between the column switch unit and the relay coils. It is shown as an electronic unit, but its purpose is not obvious. Perhaps faulty, if fitted?

A possible work around would be to connect a blocking diode between the main beam, and dip beam control wires, so that the main beam operated the dip beam, but not the other way round. Specific wiring info, and correct sense of the diode connection would be required.

Many thanks for your reply.

A wiring diagram would be a good start for me, but haven't found one yet !

I will have a look and try and find the 'electronic unit' if one exists.

My mates vehicle is give or take a couple of months the same age and exact same model. Some experts tell me that mine is correct whereas others tell me something has either failed (electronic unit) or that a previous owner has adapted it to work this way.

I cant see any reason why it would be better to turn off the dipped beams when Main beam is selected as the bulbs are in separate light units so heating shouldn't be a problem. All very confusing !

Tranby,

The switch control unit appears to be part of the 5 way push button assembly in the centre of the dash.


Road legal halogen headlamp bulbs are normally of 60W rating. A pair will pull about 10A, and my alternator is only rated at 90A. I would be doubtful as to whether that is a continuous rating.


One point to note is the following from my Owner Handbook.

"The dipped beam headlights will automatically be switched off when the main beam headlights are switched on if the front fog lights are on."

The following link is to an online (Russian?) version of eLearn. I have linked to the exterior lighting section, but as it is for x244 Ducato, it may not be applicable to your vehicle.

http://4cardata.info/elearn/244/2/244000001/244000003/244000005/244001585

Tranby said:

I cant see any reason why it would be better to turn off the dipped beams when Main beam is selected as the bulbs are in separate light units so heating shouldn't be a problem. All very confusing !

Click to expand...

It might have depended which market the van was built for. I don't know if it is still the case, but I once had a car with separate dipped and main beam lamp units. The dipped beam lamps on mine stayed on when main beam was on, but I know that was illegal at the time in some countries, and the same car sold there had dipped headlamps that extinguished when main beam was on.

The MOT manual says "Dipped beam headlamps can remain on or switch off when main beam is selected."

https://www.motester.co.uk/mot-test-of-lights/

rayc said:

The MOT manual says "Dipped beam headlamps can remain on or switch off when main beam is selected."

https://www.motester.co.uk/mot-test-of-lights/

Click to expand...

In the UK yes. But don't forget that most motorhomes sold in the UK, apart from panel van conversions where the base vehicle was sourced through the UK Fiat dealer network, are built on back-to-back cabs or rolling chassis which are not manufactured to full UK specification, so whilst they still conform to UK legislation they may have a number of differences in the way that they operate.

Even today there may be differences such as foglight dropout, emergency stop signalling, DRL function menus and DRL/indicator strategy, door locking indicator behaviour, factory alarm signalling etc.

Not that any of this helps Tranby other than to confirm that things can work differently on vans that are otherwise apparently identical models.

If Tranby's vehicle (x230?) has the block of push button switches with integral switch control module, it is beginining to look like the switch control module may differ in the two vehicles. Using such a module could be a way of adapting standard wiring to suit different markets as mentioned by rayc and RS3100. The switch control panel is shown on eLearn as a rectangle with the outline of an integrated circuit in the middle. I read the integrated circuit symbol as denoting electronic contents. It could be that a link in the switch control panel is used to provde the necessary output, and that link is faulty or absent.

The above is of course conjecture based on the available information. One thing that seems to be true is that the switch control panel is difficult to access. My present feeling is, that the panel is getting the correct input when main beam is selected, but not giving the output to the dipped beam relay.

If I am correct about access to the panel being difficult, it may be that Tranby's best option is to do nothing. If wishing to try my work around, please note that the relevent wires are only 0.5 or 0.35 mm csa.

RS3100,

Despite your statement about comments not being of help, I have found them helpful in developing my ideas.

Communicator said:

Tranby,

The switch control unit appears to be part of the 5 way push button assembly in the centre of the dash.


Road legal halogen headlamp bulbs are normally of 60W rating. A pair will pull about 10A, and my alternator is only rated at 90A. I would be doubtful as to whether that is a continuous rating.


One point to note is the following from my Owner Handbook.

"The dipped beam headlights will automatically be switched off when the main beam headlights are switched on if the front fog lights are on."

The following link is to an online (Russian?) version of eLearn. I have linked to the exterior lighting section, but as it is for x244 Ducato, it may not be applicable to your vehicle.

http://4cardata.info/elearn/244/2/244000001/244000003/244000005/244001585

Click to expand...

Many thanks for the link
The fog lights are one thing I haven't yet tried, but upto now they have been switched off when I was trying. I will let you know how I get on

RS3100 said:

It might have depended which market the van was built for. I don't know if it is still the case, but I once had a car with separate dipped and main beam lamp units. The dipped beam lamps on mine stayed on when main beam was on, but I know that was illegal at the time in some countries, and the same car sold there had dipped headlamps that extinguished when main beam was on.

Click to expand...

Hmmm that could possibly make sense as mine is LHD so could have been modified for a specific country. Perhaps I am look for a solution to a problem that doesn't exist

Thanks for your reply