Number Plate Bulb Issues (No Power)

[Chris_pickford94]

Yeah you've got the right idea

It could be something as simple as a pin in the multi connector

I've had it before on headlights where one of the pins comes loose and when the two halves of the connectors are pushed together it moves the pin out of the way and doesn't make contact

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[wase16ll]

sorry folks, but im missing something here.

again, if ive read this right, you are saying you only have 12v on one side of the fuse with sidelights on, but not the other??

thats basicly the same as if it was a blown fuse is it not???

i'll try and explain the circuit again, see if i can simplify it as there seems to be a misunderstanding somewhere

firstly the battery power is supplied to the light switch

when you switch on the sidelights, power flows to the numberplate lamps via fuse 33, in other words fuse 33 should not have 12v till sidelights are switched on, and when they are you should have 12v flow through that fuse..so if you only have 12v on one side of the fuse there is a problem with that fuse.

there are a couple of wires spliced into the no plate circuit between the fusebox and the lamps, one goes to the multifunction module, one goes to hazard switch..again, you should only have power to these once the sidelights have been switched on, there is also a further splice from the multifunction that supplies power to sidelights on warning lamp in instrument panel.

so to carry out a full and correct voltage test, proceed as follows.

connect negative probe to an earth point..making sure its a good earth throughout the testing procedure, by connecting to a positive contact that you know works..such as a different live fuse..once you know your voltmeter earth contact is good then next step.

connect positive probe to fuse 33..should read 0v

switch on sidelights and connect positive probe to fuse 33 again, should now have 12v on both sides of fuse, if only one side has 12v, check/replace the fuse..if on both sides then next step.

you now need to confirm you have 12v leaving the fusebox, as you know where the splice is located for the multi function this will be the quickest way to test it...with sidelights on you should have 12v at this connection, if not then there is a break between fuse33 and this connection..next step go to A...if there is 12v at this connection, go to B

A...need to locate the wire as it leaves the fusebox, so following the colour code i gave in an earlier post, you will be looking for an Orange and Black wire..if necessary pierce the wire carefully to check for 12v, if there is no 12v here, then the break is between the fuse 33 and the point that you check, most likely an internal problem in the fusebox or the connection as it leaves the fusebox...if you do have 12v here, then you need to follow the wire and keep checking till you reach the point 12v is lost...

B...the Orange and Black wire continues from the multifunction splice to the lamps..so follow this wire all the way between these points with periodic tests by piercing the wire till you reach the point you lose the 12v...

going from previous tests, the problem is most likely between the power supplidf at fuse33 and the splice for the multifunction, as you stated the sidelight on warning bulb on the instrument panel is no longer working either.

if your claiming that there is 12v only on one side of the fuse, then that sounds like a problem with the fuse itself

[Chris_pickford94]

Hi wase, I was assuming he was testing for voltage without a fuse in the fuse holder ...

But your last reply makes it a lot clearer as to the route of the wiring and I agree that the fault will then be somewhere between the fuse box and the multifunction module because of there being no light indicator on the dials when sidelights are turned on

Assuming that the fuse is fine

And also that there is a good earth?

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[wase16ll]

Hi wase, I was assuming he was testing for voltage without a fuse in the fuse holder ...


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i did wonder, but it wasnt clear wether the fuse was removed or not which is why i thought best to comment on it :)

[BryzeMo]

Hi guys. Right finally we have fixed my problem. I checked the cable from the back of fuse 33 to the multi connector and no continunity so i have managed to replace this cable which i believed to be broken and hay presto! Number plate lights, hazard switch and instruments all back working again. Phwee that was an electrical nightmare trying to trace wires that are in such tight spaces but i obviously couldnt have done it without all your help guys. Will def be visiting this site again for any issues i hav with my motor.

Thanks again

Bryan

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