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Garryoke

How To Reverse The Polarity On Headlight Bulbs And Fit Sidelights Mk4.

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Oh well, there was me scanning Ebay one night with a few beers in me and wow!! Mr Hong Kong is selling a lovely set of H4 LED bulbs for my Rav 4 at the cheeky price of six quid and side lights at £1.99 each! Bargain : )

A few weeks pass, they arrive and Noooooooooo............ They are reverse polarity (the positive and negative are reverse to what we have over here) - and has anyone ever tried fitting new sidelight bulbs if your hands are larger than a cats??? Impossible.

So guys, what first comes to mind to make the H4's work is to cut and swap the wires. But is there any other way, or an adapter etc?

Garry

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See me Gaz min.........see if ah had spent ONLY a ten pound piece on this "fire under the bonnet in waiting"..........ah would bin the far king lot, mate........nae offence meant....none taken.

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See me Gaz min.........see if ah had spent ONLY a ten pound piece on this "fire under the bonnet in waiting"..........ah would bin the far king lot, mate........nae offence meant....none taken.

Wise words indeed from North of the border, to the point as per usual.........P.M me for any help with translation Garry.

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You just reminded me of ma first girlfriend there, Paul.........Lisa Lane............translate that wan....lol.

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Almost every vehicle manufactured these days is -ve earth/chassis. To reverse polarity (for LED devices) you need to isolate the lamp's 'ground' connection from the chassis, and swap over the incoming wires. If the headlight unit (lampholder) is not grounded, but relies on a ground connection, it's even easier - just swap over the two connections.

Suggest you test out with an old LED (the flat on it is the cathode, -ve, connection) before coupling up your new acquisitions.

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..........or ye could just chuck them in the Dan Flynn as I suggested.........already too many wee sidelight bulbs have imitated Chernobyl after a short (?) time with 12v supply, but surely an H4 headlight bulb, that ye need to rewire FFS, poses more of a problem.......?

Jist a thocht......

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Could anyone translate far king ?? I'm having trouble with that one ..

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Could anyone translate far king ?? I'm having trouble with that one ..

Distant monarch?

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Could anyone translate far king ?? I'm having trouble with that one ..

Should one see fit to remove the "ar" letters, Charlie, and substitute with "uc", the auto sensor may JUST click in......LOL.

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Far King is my virtual brother................North of G0ds little acre in Chesh hire

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The H4 lamps can't be bright enough in LED form? Bet they don't do dipped and full beam either. Best to ditch them and just get some road legal nighbreakers or silverstar 2.0's.

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The H4 lamps can't be bright enough in LED form? Bet they don't do dipped and full beam either. Best to ditch them and just get some road legal nighbreakers or silverstar 2.0's.

Sense, Lee min......in English tae.......

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Having now Googled (briefly) H4 LED headlight bulbs . . .

post-70734-0-97124900-1379004672_thumb.j post-70734-0-30538700-1379004914_thumb.j

I have to say that it is extremely unlikely that these lamps will operate efficiently, legally and without uncontrolled dazzle in headlight units designed for "point source" halogen filaments. The light source occupies such a large area, it makes a nonsense of any notion of a focussed beam.

IMO, keep well clear of this marketing opportunity.

Chris

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I must say, I'd love to see how good (or bad) these things are. You could make a short loom from male and female spade terminals. I can't imagine that one of the manufacturers wouldn't be on with them if they were any good. However, something followed me the other day and I had to dip the mirror because they were so bright and that was in the day. Some of those concentrated through a headlight reflector might turn out pretty impressive!

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I'd be worried by the heat generated. The LED sidelight capsules I tried melted internally.................................

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Shouldnae have swallowed them then.........did you end up desperate to go for a light..?

Witheld..........

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Shouldnae have swallowed them then.........did you end up desperate to go for a light..?

Witheld..........

I just ended up with a flash in the pan......................

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Shouldnae have swallowed them then.........did you end up desperate to go for a light..?

Witheld..........

I just ended up with a flash in the pan......................

Must be Friday. The jokes are in the toilet........................

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Toilet humour, someone is taking the plish.........

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Slightly off topic, but I have started using LED bulbs in light fittings around the house where possible. The lumens/watt are getting mighty impressive now and whereas maybe just 2 years ago LEDs would only be good enough for a bit of accent lighting or to provide a little bit of illumination on a landing, for example, now they hold their own against ordinary filament lights, halogen or CFL lamps, and at much reduced power consumption and way better lamp-life.

It can't be too long before proper type-approved LED headlamps - Main & Dipped - will be around.

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"It can't be too long before proper type-approved LED headlamps - Main & Dipped - will be around."

Seconded! And, as you say, hopefully properly designed as retrofits - unlike the items above.

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Not sure about H4 but my local motor factor, which is like an international Halfords (Norauto), sells various LED replacements for normal bulbs. I can't believe they'd be on sale (for long) if they didn't work or were dangerous. I wonder how much of the problem is caused by you getting cheap stuff from Hong Kong.

A club member offered me a free pair for sidelights for my other car, theyd only cost him two quid. I thought he was generous but they stopped working after 3 mths. I then spent £12 in aforementioned shop for replacements and they've been fine.

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Oh Hoovie, nearly all my house now has LED lamps, the good stuff has been available for the last two years (GU10 50w halogen should be replaced by about 350lumen LED), the main issue has been the price and at last that's dropping from the 10 each I used to pay to closer to 5 now. Last month I finally managed to replace the four 20w G9s in the dining room for suitable 2w LEDs, and that's it. Electricity prices these days are ridiculous!

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Don't forget though that although Halfords sell things like led sidelight bulbs they aren't legal on the road. quote from Halfords description..."For off road or show use only. These lights must not be visible to other road users. Not legal for use on public highways."

That's how they sell lots of rubbish to kids. Disclaimers in small writing.

Just like those +90% halogen lamps that blind the f out of us.

They also look very blue alongside the halogens. Just my 2p rant worth. ;)

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Rant on Lee min.......Honda Civic behind me must have been filming porno movie last night......whole area around it was diffracted blue haze......absolutely illegal.

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