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Cox3120

New Member

• Aug 12, 2012

• #1

Hi all
I took my land rover for an MOT and it failed on the dip beam staying on when the high beam is turned on. I was told that this is normal for these land rovers but can anyone else confirm if this is true, if not can you clever people give me some clues on what may be the problem. I have been surfing the net most of the day and as of yet I have not found the answer hope you can help.
Thanks matt

 

mad git

New Member

• Aug 13, 2012

• #2

Your wiring needs looking at

 

dominicbeesley

Well-Known Member

• Aug 13, 2012

• #3

Or the switch has been replaced with a wrong un.

I never knew it was a fail to have dipped on full on at same time though...Just had a quick look at the UKMOT site and I'm not sure that it is. It merely mentions that the main beams must go off when you use the dip control. Reading some other forums it sounds like your tester may be mistaken...par for the course really.

 

dominicbeesley

Well-Known Member

• Aug 13, 2012

• #4

Having said that I'd still wire them up properly, been doing a quick thought experiment - results won't be very accurate but indicative!

Say you dipped beams are 50W each so 100W. If you drive for an hour with them on for no reason that's 60*60*100 = 0.36MJ (Mega Joules) used.

That energy needs to come from somewhere and it will come from the petrol/diesel. For a petrol motor petrol contains about 34MJ per L of useable energy.

Now say your engine is 20% efficient (probably a bit generous for a Landy) and your alternator about 50% (about right) then you will use

0.36 / (0.2 * 0.5 * 34) = 100mL

or at todays prices about 14p an hour extra....

 

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Rangiedaz

New Member

• Aug 27, 2012

• #5

I'm a tester, and I'm not sure its a valid fail, gonna check first thing in morning!

 

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Telboy111

New Member

• Aug 28, 2012

• #6

gotta be faulty dip switch just get a new one.

 

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Rangiedaz

New Member

• Aug 28, 2012

• #7

Rangiedaz said:

I'm a tester, and I'm not sure its a valid fail, gonna check first thing in morning!

Click to expand...

Shouldnt fail on this, infact quite a few of the modern cars i've tested today have the dipped beam remaining on when high beam is selected. As previously mentioned, it should only fail if the main beam stays on when dipped is selected