h4 bulb wiring question

**spyghost** · May 7th, 2009 03:20 PM

hi,

in an h4 bulb, if you face the terminals, the top is the low beam, right is the high beam and left is the common. this is universal and standard across all h4's no doubt.

question is, why are there some cars wired such that the common is (+) while some cars are wired with the common being (-)?

what are the advantages/disadvantages of those two configurations?

**kapitan88** · May 7th, 2009 04:01 PM

not sure, but, di na yata kailangan ng relay kung negative switching system (+common).

**xenonoptics** · July 9th, 2009 02:35 AM

Originally Posted by kapitan88

not sure, but, di na yata kailangan ng relay kung negative switching system (+common).

may mga sasakyan po kasi baliktad ang polarity.

kelangan lang naman po mag lagay ng wiring harness kung gamit niyo h4 na mataas ang wattage minsan kasi nasusunog yung wire or di kaya yung socket. yung iba pinapalitan ng ceramic na socket or pansinin niyo mga bagong sasakyan may grease ang socket. para po yan sakaling lumuwag ang socket niyo hindi nag caucause ng spark yun din kasi isang dahilan ng paglusaw ng socket na stock pag loos yung socket nag spark.

pag maglalagay kayo ng 100watts pataas na h4 i suggest lagyan niyo ng wiring harness , important ang relay para masmalakas ang buga ng bulb niyo directa siya kukuha ng koryente sa battery