Sealed Beam to H4 Conversion Wiring

Geoff-R

Club Member
Hi all,

Just looking for a few pointers. I've removed the LHD old sealed units off my car and have a set of new H4 units. I'm wanting to wire them up but as I've read the H4 units will cook the original wiring without a new relay in place. Can anyone tell me where I can either purchase the conversion harness with relays etc or where I can buy the components in order to build my own conversion harness.

Cheers
 

Jimbo

1978 260z in yellow
Club Member
the wiring is pretty simple to make your own but there are kits allready out there you can buy so you could allways chop the wiring and extend or shorten it as needed.
 

Moriarty

Well-Known Forum User
Moriarty out of interest have you had experience of using led h4 bulbs?

Yes I have them fitted
Simple plug and play, they take a fraction of the current, run way cooler and produce a strong white light, plus the kits usually come with optional filters to change this, if that's your thing.

Not cheap at £10 - £15 per bulb but you wont have to modify anything plus you'll never have to buy a bulb again
 

Jon_Flynn

Club Member
Yes I have them fitted

Simple plug and play, they take a fraction of the current, run way cooler and produce a strong white light, plus the kits usually come with optional filters to change this, if that's your thing.



Not cheap at £10 - £15 per bulb but you wont have to modify anything plus you'll never have to buy a bulb again



And these just replace the stock bulbs with no other wiring needed?

Got a link? Could be a worthwhile upgrade rather than changing the lighting setup in full


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Geoff-R

Club Member
the wiring is pretty simple to make your own but there are kits allready out there you can buy so you could allways chop the wiring and extend or shorten it as needed.

I think I would make it myself as the cost of a kit Vs an hour or so of my time to make it would be worthwhile.

Moriarty, pop up some pictures if you can, that would be useful to see, cheers :thumbs:
 

Jimbo

1978 260z in yellow
Club Member
That's fair enough, I think the last ready wired kits I saw were on eBay for about £35
When I made my own there wasn't much in it price wise but I know mines better quality


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Geoff-R

Club Member
That's fair enough, I think the last ready wired kits I saw were on eBay for about £35
When I made my own there wasn't much in it price wise but I know mines better quality


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That's it, if you make it you know how well it's been made. Out of interest what amp relays did you use?
 

Jimbo

1978 260z in yellow
Club Member
40amp with built in fuse holder for the main live input
Used to be able to get them from halfords


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Jimbo

1978 260z in yellow
Club Member
You can still get them on eBay for £5
A 30amp on will do fine
A h4 bulb is 55 watt low beam and 60 high beam
55 devided by 12 is 4.6 amp x 2 is near enough 10 amp so the one relay for low beam will have no issue
60 devided by 12 is 5 amp so x2 is 10 amp again so the current to light both dipped and main isn't going to be much more than 10 amp so standard 30 amp relay will be fine


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Jimbo

1978 260z in yellow
Club Member
Just make sure you fuse it well as close as you can to the battery you don't want a short


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Moriarty

Well-Known Forum User
And these just replace the stock bulbs with no other wiring needed?

Got a link? Could be a worthwhile upgrade rather than changing the lighting setup in full

Just Google LED H4 bulb....... pages and pages will result

Moriarty, pop up some pictures if you can, that would be useful to see, cheers
Just exactly what should I show a picture of ?

Two options

1. Spend cash/time on a bespoke loom/relays and then debug and with due respect few people on here have decent practical skills plus you're still left with a filament bulb that that takes significant current .............or

2. Spend £30 on bulbs and plug them in.

Horse, water, lead
 

Rob Gaskin

Treasurer
Staff member
Site Administrator
Had this through the post recently, it might help understanding:
 

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Geoff-R

Club Member
Just Google LED H4 bulb....... pages and pages will result

Just exactly what should I show a picture of ?

Two options

1. Spend cash/time on a bespoke loom/relays and then debug and with due respect few people on here have decent practical skills plus you're still left with a filament bulb that that takes significant current .............or

2. Spend £30 on bulbs and plug them in.

Horse, water, lead

It was just to get an idea of what they looked like fitted and running to weigh up options of going the wiring route or fitting led bulbs. Fear not I will Google :thumbs:
 

Moriarty

Well-Known Forum User
These are the ones I use

VANSSI 9003 H4 Headlight Bulb CREE LED 30W High Power DIY Color Hi/Lo Dual Beam Headlight Bulb (Pack of 1)
 

Moriarty

Well-Known Forum User
Any photo f the light emitted will be will be skewed (camera, lighting conditions etc)
Other than that it looks just light a standard headlight
 

Jon_Flynn

Club Member
These are the ones I use



VANSSI 9003 H4 Headlight Bulb CREE LED 30W High Power DIY Color Hi/Lo Dual Beam Headlight Bulb (Pack of 1)



Thanks Moriarty, and these just fit into the he standard bulb housing? Going to order some this afternoon


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