Wiring harness for HID

[raquino]

When installing plug and play HID's on projectors, do you use new relay wiring harness or just use stock oem headlamp wiring? What's the advantage of using separate harness from oem harness?

[arjay17]

better use the harness than stock. AFAIK mas makapal yun harness and baka masunog pa yun OEM wires w/ HID bulb in the long run since HID has higher voltage than halogen. Some even say that even yun buga ng ilaw bag naka harness.

[confused shoes]

The stock single beam halogen is normally 55w. And the stock HI/LO halogen is normally 55w(low)/60w(high).

If you will compute the maximum current these lamps will draw that would be P = E x I (recalled from Physics). Where P is power, E = voltage (12v in this case), I = is the current that will pass through the harness. That will be I = 60W/12V = 5Amperes (high beam).

Check the HID ballast on how much max current it will draw. You can find that on the ballast label. An HID 35W ballast will normally draw 3.2A which is still lower than the current drawn by the stock halogen. A 55W HID ballast is rated at 5A and It is the same as the current drawn by the stock halogen(high beam).

Hope it helps.

[D3nb3r]

When installing plug and play HID's on projectors, do you use new relay wiring harness or just use stock oem headlamp wiring? What's the advantage of using separate harness from oem harness?

sir, stock oem headlight wiring will not be enough to ignite your HID bulbs. unless your oem wiring was designed for HID bulbs. if not then better use correct harness and ballast dahil ang HID bulbs needs a very high voltage(similar to sparkplug) during initial start-up to ionize the halide salts and xenon gas inside the bulbs. garyq is one of the experts in HID's. try asking him.

[jaypee10]

better use the harness than stock. AFAIK mas makapal yun harness and baka masunog pa yun OEM wires w/ HID bulb in the long run since HID has higher voltage than halogen. Some even say that even yun buga ng ilaw bag naka harness.

mas malakas pa nga kumain ung halogen bulb kaysa sa HID kasi ang nagpapalakas lang sa HID ay ung ballast niya..dun sa halogen bulb direct siya..kaya mas magandang lagyan ng relay ung halogen kaysa sa HID or ballast..

HID has higher voltage than halogen.

higher voltage lang ang output niya...kasi nga may ballast...ung ballast ung nagpapalakas sa kanya..

[NightRock]

when I got my HID kit I have notice the difference with the OEM wiring than than the kit wiring in the kit looks letter.. but I still opted to put relay I also compare the performance.. mas mabilis lumiwanag ang may relay compare sa wala..

Buts its only me base on my experience as I tried both of them.

[D3nb3r]

Hope this answer your question (from HIDretrofit.com):
There are a lot of aspects to controlling the HID system and ensuring your car's wiring is safe.
A wiring harness is designed to draw power directly from the vehicle's battery. This is done through the use of an inline fused relay box. A bi-xenon wiring harness also has built-in diodes to keep power supplied to the HID ballast at all times during high & low beam operation.

A common issue is whether or not to use a wiring harness. It's always recommended that a wiring harness be used when upgrading to an HID retrofit setup, but is it really required? The answer depends on your system components & setup.

If, for example, you are utilizing generic no-name brand ballasts, a wiring harness is a must. The reason behind this is that generic ballasts have unreliable voltage requirements. More often than not they draw too much current upon startup & while the bulb is on, and can damage your factory halogen wiring.

Let's say you're using higher quality OEM ballasts. A wiring harness is ultimately up to your discretion (or your retrofitter's). A variety of vehicles come with HIDs from the factory and they are already setup to meet the electrical requirements of an HID ballast. If you are upgrading to a projector retrofit on one of these vehicles, a wiring harness is not needed.

The same could be said for a non-HID equipped vehicle as long as high quality ballasts are being used (such as OEM spec ballasts or an All Digital Morimoto ballast).

A good quality ballast (such as an OEM spec or an All Digital Morimoto) will very briefly use a higher current draw during startup (nominal at around 9-10 amps for about 1/5th of a second) and settle at 3-4 amps during the bulb's on cycle. This situation generally doesn't require a wiring harness setup.

[raquino]

Thanks everyone for the input. I think it is always safer to use a wiring harness to prevent any problems with the original headlight wiring.