Hello, I though some one here might be able to give me some insight. What I am trying to do is make H4 headlights operate properly in a car that had 9005/9006's. Since the 9005/6 are single filament and they both come on when the high beams come on I cant just cut and splice them to the H4 connector, otherwise both filaments in the H4 bulb will be on at the same time and the bulb burns out quicker. I'm just not sure about how many relays I need and how to hook up so the high beam triggers the relay/s to shut the low beam off. If you could post a pic of the relay setup or just what wires go where(30 ,86,87,87a etc) on the relay would be great. Thanks all

 

Well heres what I was thinking tell me if I'm wrong. hook 85 up to the high beam power(spliced, power will still go to the high filament as well) . hook 86 to the ground. splice 30 and 87a into the low beam wire( does this matter if its the power or ground wire?) and leave 87 blank. when the high beam is switched on it will cut the circuit from 87a to 87 and thus turning the low beam off right? does this make sense?

 

You got it. I mean, you'd have to be more specific about "the low beam wire" for me to be 100%... but it sounds like you know what you're doing.

It doesn't matter if 85 is power or ground, as long as 86 is the opposite. It doesn't matter if 30 is power or ground, as long as 87 and 87a are the opposite or open.

 

I'm thinking technically you don't have to use any relays. 9005/9006 has two different connectors that go to two different bulbs. H4 has one connecter with three wires ( high and low + ground). I'm sure you already knew that but to prove my point, i'm thinking using the two positive wires from the 9005/9006 you can just slice it into the h4 harness, skipping the relays and wire both sides seperately or use two relays to wire up one side which will output to both bulbs. However if you were using higher powered bulbs or HIDs then a relay would be recommended.

If you use one relay, then wouldn't your lights always be on? for example if it's in the resting position(no current or headlights off) then one beam would be on, then if it's in the active(powered or headlights on) then the other beam would turn on.

I know this post gets confusing just read carefully and I think you'll get it or correct me if i'm wrong somewhere.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by suspendedHatch &raquo;</TD></TR><TR><TD CLASS="quote">You got it. I mean, you'd have to be more specific about "the low beam wire" for me to be 100%... but it sounds like you know what you're doing.

It doesn't matter if 85 is power or ground, as long as 86 is the opposite. It doesn't matter if 30 is power or ground, as long as 87 and 87a are the opposite or open.</TD></TR></TABLE>
85 was going to be +(from the high beam wire) and 86 was going to ground. then the + on the low beam was going to go from 87a to 30 and out to the bulb which is then grounded. when the high beams come on it trips the relay turning power to 87 which is open and shutting the low beam off. does this sound right?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dad0c402 &raquo;</TD></TR><TR><TD CLASS="quote">

If you use one relay, then wouldn't your lights always be on? for example if it's in the resting position(no current or headlights off) then one beam would be on, then if it's in the active(powered or headlights on) then the other beam would turn on.

I know this post gets confusing just read carefully and I think you'll get it or correct me if i'm wrong somewhere.</TD></TR></TABLE>

I think you might be misunderstanding. The way I have it setup in my head is that when the power is turned on to the headlight low beam it goes right through the relay(from 87a to 30), when the high beam is turned on it lights the high filament as well as tripping the relay turning the low filament off(85 to 86), make sense. I think I have it right but Im not a wiring expert so I was just confirming. if this makes sense to anyone , please tell me if im right or not. thanks

 

bump, do I have this right?

 

I still say you can skip the confusion and wire it up with no relay.