Zafira tail/brake light issue

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Driver side rear tail & brake light not working .
Have replaced bulb & tested cluster on opposite side & works perfectly.
Checked fuses (doesn't seem to be a split fuse set-up )
All other lights on the cluster work fine when plugged into the drivers side .
Now , I've checked the voltage on the good side across the (bulb) track & its about 3v and about 13v on the bad side (not sure if that's the best way to measure ?)
It's a 06 Zafira B , can anyone give any pointers before I call the auto spark ?
Cheers .
 
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Assuming you have popped the correct bulbs in ( dead easy to insert a twin filament bulb where there should be a single one etc) I'd make sure there is a good earth on the faulty side, and then check for voltages from the plug itself at the back of the lamp unit.
Just check the front sidelights are on, will you?
John :)
 
It's the correct bulb & ive tested the cluster on the other side & it works fine.
Out of curiosity if the earth was faulty why does everything else on that cluster still work ?
A wiring diagram would be handy .
Front lights are fine .
 
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You have done all of the sensible checks!
I think you have missed a dud fuse somehow.....according to Google Garage the offside rears are fused but there's no reference to the nearside units - but they will be fused too.
There will be one fuse box in the engine bay, and another in the cab somewhere. I'd guess you are looking for a 10 amp fuse.
John :)
 
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I'm hoping it's a daft missed fuse , the owners manual doesn't mention split fuses & ive checked all the 5amp in the rear box ( did find out why my front charger hasn't worked for years) felt like a glorious moment only to realise it wasn't the fuse I was looking for:(
I'll pull out the front fuses tomorrow with a fresh head & approach :)
Cheers for the input & I'll keep you posted (y)
 
It's the same establishment that provides Dr. Google......you know the site - you ask about an ingrowing toe nail to find that death is imminent :mrgreen:
John :)
 
If you've got 3 volts being registed, then it can't be the fuse, as you'd be getting 0v. You've either got a dodgy earth, or a dodgy feed, so check live on the bulb feed, and earth onto the body work. If you get 13v, then it's an earth issue, and if it's 3v, then it's a feed issue, and you'll need to trace it back till you find the iffy connection.
 
Just to clarify
3v was measured across the working light & 13v measured across non working light , measured across the bulb track.
Regards the potential earth issue !!!
Would an earth fault not affect all the lights on the cluster ?
 
Any faulty earth can manifest itself by creating all sorts of spurious voltages, as power to the lamps try to return through other filaments and so on.
It doesn't seem to be the fault here though!
John :)
 
How are you connecting your meter?

I just measured across the tracks on both sides to compare readings .
Good side reading 3v
Bad side reading 13v
I've tried the faulty cluster on the other side & it works perfectly.
 
3v was measured across the working light & 13v measured across non working light , measured across the bulb track

Now that just doesn't seem sensible; what sort of bulbs are they, as even LEDs would be 12v, not 3v. I'm flumoxed on those readings. What's the voltage of the lamps.

Would an earth fault not affect all the lights on the cluster ?

It would depend on whether it's solid backplate carrying the voltage, or wired point to point - and whether theres any corrosion or something stopping a good contact.
 
OP, does the holder look like this?...

s-l1000.jpg


All four lamps are single filament.


even LEDs would be 12v, not 3v. I'm flumoxed on those readings. What's the voltage of the lamps.

The Zafira B uses a single filament bulb for the stop and tail lamp. It's then pulse width modulated for the tail light, hence the 3v reading that the meter thinks it can see, you'd need an oscilloscope to check it properly!!
 
Ouch, this one just went way over my head. Would that imply that the 13v reading shows the pulse width modulating wasn't working on the duff side then.
 
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