Hi guys, 1st post for a while, so be gentle...

We've just got a 2013 Monty and DRL's work fine.. I bought some led bulbs with the can bus module in built and they don't work.. They are both bayonet fit, however my mate is an electrician with a circuit tester and he's found the polarity of the bulbs are different.. On the bulb holder and standard bulb the + is the outer ring with the - in the centre.. On the led's the + / - are ther other way round as he tested it with 12v power and both LEDs work, off the car..

Apologies in advance if I'm being a total numpty...

Any ideas ?

Cheers in advance..

Edited 13 March, 201610 yr by skomansteve

Have you tried turning the bulbs round in the holder?

Cheap bulbs are generally crap, get something better like Cree

Yes I tried that, but with a bayonet connector it shouldn't make any difference...thanks..

What does the base look like? Have you looked at the new and old bulbs from the base? I thought the S25 bulb was a double contact at the bottom, which is different to the required single centre contact, I may be wrong though

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I have a 2011 and had the same problem, what i did was cut the two wires for the bulb holder and swapped them round, then worked fine , there is a thread on here somewhere showing exactly what to do.

Edited 14 March, 201610 yr by DIZZY3

I have a 2011 and had the same problem, what i did was cut the two wires for the bulb holder and swapped them round, then worked fine , there is a thread on here somewhere showing exactly what to do.

I was thinking along the same lines... Looks like that'll be the answer...

In answer to Jonro's post, there's only a single central terminal on the base of the bulb..

I still think that the answer lies somewhere in the S25 listing.

My 2013 monte has had several different DRL bulbs as I was never happy with them until I got the 80w CREE bulbs, none of them where S25 and all of them worked straight out the pack.

Good luck getting it sorted.

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I still think that the answer lies somewhere in the S25 listing.

My 2013 monte has had several different DRL bulbs as I was never happy with them until I got the 80w CREE bulbs, none of them where S25 and all of them worked straight out the pack.

Good luck getting it sorted.

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Hi Jonro, the bulbs are P21W like this

What I don't get is why the polarity is opposite to what I think it should be, I.e the centre contact should be + and the outer bulb casing should be the earth.. Am I missing something? I know yours worked, but I don't want to to the expense of buying Cree's only to end up with the same problem...

Cheers.

Steve.

Edited 14 March, 201610 yr by skomansteve

It's a strange one. I think that the S25 in the description is something to do with it, it just glares out as being something unfamiliar. I'm convinced it pertains to it being reversed polarity although I can't find anything to support this.

Have you tried contacting Ultra HIDS throw go their eBay shop and asking, perhaps it's just a faulty bulb?

I know the reverse light is the same fitment as the DRLs so only other thing I can suggest is to try the bulb in the reverse light and try the reverse bulb in DRL see what if anything you can draw from that.

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There are definitely other posts about this. It seems it's not unusual to have to swap the wires.

There are definitely other posts about this. It seems it's not unusual to have to swap the wires.

Yup, finally sorted it with a tool to remove the wiring connectors - swapped the wires around and hey presto the led's work fine...

Apologies for the crap photo, but here's one to show they work..

Are there bulbs lit in the headlight cluster too or is that the flash from the camera?

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Ha yes it is just a reflection of the flash.. :-/

To swap the wires around without having to cut them which I wanted to avoid, it just needed this tool..

http://www.ebay.co.uk/itm/322028748293?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Edited 27 March, 201610 yr by skomansteve