Relays & heavy wire to upgrade headlights

[FleaDog]

I gave the instal a go last night but got stuck.

 

I set up both main feed/hot power wires/fuses off the battery positive to #30 on both relays (high, low).

 

To trigger the relays I used the stock harnesses (wires that usually plug onto the bulbs). For the low beam relay trigger I used the driver side low ground to #85, and the driver side feed/hot to #86. For the high beam relay I went over to the passenger side and used the pass high ground to #86, and the pass side feed/hot to #85.

 

From here is where I get confused...

 

Where do/what configuration do the dual feed/hot (87, 87a) OUT of the relay terminals for each relay get routed to.

 

Where the grounds (high/Lo for each) from both bulbs feed back into? -

The existing light wiring feed/grounds are being used to control the relays but then what do you do with the ground terminals on the lights/bulbs themselves?

 

tried searching for a switched ground schematic but no luck

[edrach]

I'm confused too. But there's no need to wire the control wires to both the driver and passenger side. You have both the high and low control on each socket; passenger side or driver's side, take your pick. Sadly that doesn't solve your problem. I'd suggest going back to Daniel Stern Lighting and get a proper wiring diagram for a ground switched system like you have.

Edited October 13, 2012 by edrach

[FleaDog]

I'm confused too. But there's no need to wire the control wires to both the driver and passenger side. You have both the high and low control on each socket; passenger side or driver's side, take your pick. Sadly that doesn't solve your problem. I'd suggest going back to Daniel Stern Lighting and get a proper wiring diagram for a ground switched system like you have.

 

i hear u bro, he doesnt have one i asked. i emailed him earlier today but didnt hear back.

[edrach]

i hear u bro, he doesnt have one i asked. i emailed him earlier today but didnt hear back.

That's more than annoying. If the rain stops this weekend, I'll be installing mine. Looks straight forward, but you never know until it's in and working.

[Fairtax4me]

Terminal 87a will only be present on a 5 pin relay. I thought it just came with 4 pin relays? You should have: 85, 86, 87, and 30.

 

This process just changes the bulbs from switched to ground to load to ground. So the bulbs now need to be grounded to the body of the car, or run a clean heavy gauge (same as your power wires) ground back to the battery. You can follow the diagram posted earlier to run the load side wires. Remember the new hi/low power wires for the bulbs need to be SPLIT so they go to BOTH bulbs.

 

Big thing here: Left and right side headlamp hot wires are different colors.

Left headlamp:

Red = High beam Ground

Red/Blue(or purple) = 12V in (fuse 24)

Yellow/Blue(or purple) = Low Ground

 

Right Headlamp:

Red = High Ground

Black/Yellow = 12V in (fuse 26)

Yellow/Blue(or purple) = Low Ground

 

For the Low beam relay:

86=low ground > hi/lo sw. (Y/B)

85=original Hot (B/Y on right side, R/B on left side)

87=new wire split out to BOTH low beams.

30=Battery 12V (be sure to fuse this near the battery)

 

For the high beam relay, put this one on the opposite side (if your low relay is on the drivers side, this one should be on the passenger side)

 

86=Hi ground (Red)

85=Original hot (B/Y on right side, R/B on left side)

87=new wires to BOTH High beams

30=Battery 12V. (be sure to fuse this near the battery)

 

Now your bulbs should be something like

Low pin = wire from low relay

high pin = wire from high relay

ground pin = wire to chassis ground

 

The 85 and 86 pins can be reversed and still work. Same with 87 and 30. The relay coil doesn't care which side is ground or power. As long as you keep the control wires on the coil side, and the load wires on the load side.

This schematic view might help or it might not. :-p

 

Here's my attempt at making this wire diagram make sense.

 

I would also wire the new fused power wires to the battery rather than the alternator. Alternators can produce uneven voltage and current that can sometimes be seen as a "flicker" in the light output. The battery has the effect of smoothing this out. Technically it should do this at the alternator output as well, but with the power wires at the battery you can save a few feet of wire, and don't have extra wires coming off the engine to worry about getting snagged or be in the way if you need to change a belt.

Edited October 14, 2012 by Fairtax4me
FIXED INCORRECT WIRE COLORS, new info for left/right headlamp wiring, some spleling, also fixed incorrect info in picture.

[edrach]

I would also wire the new fuse power wires to the battery rather than the alternator. Alternators can produce uneven voltage and current that can sometimes be seen as a "flicker" in the light output. The battery has the effect of smoothing this out. Technically it should do this at the alternator output as well, but with the power wires at the battery you can save a few feet of wire, and don't have extra wires coming off the engine to worry about getting snagged or be in the way if you need to change a belt.

It's so nice to have people here who understand this stuff. I agree with wiring to the battery also; battery acts as a big capacitor to "clean" up what comes out of the alternator. Nice write up.

 

I'm not so sure why the original diagram suggested wiring to the alternator. Maybe they wanted to eliminate the small voltage drop between the alternator and the battery to get the maximum light output. Makes no sense to me.

[FleaDog]

 

Now your bulbs should be something like

Low pin = wire from low relay

high pin = wire from high relay

ground pin = wire to chassis ground

 

 

great tips.

 

to clarify, on the bulbs, so the pin that was for the common hot is now what youre calling the ground pin?

 

thx

[FleaDog]

Terminal 87a will only be present on a 5 pin relay. I thought it just came with 4 pin relays? You should have: 85, 86, 87, and 30.

 

This process just changes the bulbs from switched to ground to load to ground. So the bulbs now need to be grounded to the body of the car, or run a clean heavy gauge (same as your power wires) ground back to the battery. You can follow the diagram posted earlier to run the load side wires. Remember the new hi/low power wires for the bulbs need to be SPLIT so they go to BOTH bulbs.

 

Red = hot

Red/Blue = low beam ground

Yellow/Blue = high beam ground

 

For the Low beam relay:

86=Red/blue, low ground (to hi/lo sw.)

85=red, original Hot

87=new wire split out to BOTH low beams.

30=alternator 12V

 

For the high beam relay, put this one on the opposite side (if your low relay is on the drivers side, this one should be on the passenger side)

 

86=Yellow, Hi ground

85=red, original Hot

87=new wires to BOTH High beams

30=alternator 12V.

 

Now your bulbs should be something like

Low pin = wire from low relay

high pin = wire from high relay

ground pin = wire to chassis ground

 

The 85 and 86 pins can be reversed and still work. Same with 87 and 30. The relay coil doesn't care which side is ground or power. As long as you keep the control wires on the coil side, and the load wires on the load side.

This schematic view might help or it might not. :-p

 

Here's my attempt at making this wire diagram make sense.

 

I would also wire the new fuse power wires to the battery rather than the alternator. Alternators can produce uneven voltage and current that can sometimes be seen as a "flicker" in the light output. The battery has the effect of smoothing this out. Technically it should do this at the alternator output as well, but with the power wires at the battery you can save a few feet of wire, and don't have extra wires coming off the engine to worry about getting snagged or be in the way if you need to change a belt.

 

great tips.

 

to clarify, above where u mention the bulb pins, so the pin that was for the common hot is now what you're calling the ground pin?

 

thx

[Fairtax4me]

Yes, what before was a common hot at the bulb, is now a common ground. I want to say it's the center pin but it's been a while since I messed with the headlight wiring. I'm almost certain it's the center pin on the bulb. You can check the bulbs with a DVM to be sure.

 

Also I just checked the wire diagram since I remembered that the wire colors are different between drivers and passenger side. I need to edit my previous post with the correct info for those colors.

[FleaDog]

got it working using you instructions, thx!

 

im using the osram narva 100/90w i bought from dan stern

 

the highbeams are awesome, huge difference.

 

however, the low beams seem like half as bright as they should be... id sa about the same as regular bulbs...

 

something maybe wrong?

Edited October 14, 2012 by FleaDog

[edrach]

got it working using you instructions, thx!

 

im using the osram narva 100/90w i bought from dan stern

 

the highbeams are awesome, huge difference.

 

however, the low beams seem like half as bright as they should be... id sa about the same as regular bulbs...

 

something maybe wrong?

Measure the voltage on low side and high side relative to ground--should be pretty close the same (around 13V). If low side is significantly lower there's a problem; mis-wire, faulty relay contact. The other possibility I can think of is that on high beam, BOTH filaments are lit; on low beam only one filament is lit.

[edrach]

I installed my kit today. Just under 25 minutes start to finish. Here's the final pic: http://www.ultimatesubaru.org/forum/album.php?albumid=17&pictureid=3734. Only downside is that the Impreza has low beam lights on dim all the time for daytime use. Even the lowered voltage is enough to trigger the low beam relay. I'm not comfortable running them at full voltage during the daytime. I'll likely pull the daytime module and run without them. If I can figure some way to divert the daytime lighting to the foglights I'll do that.

 

Update: I pulled the plug on the dimmer resistor. No daytime running lights but everything else still works.

Edited October 14, 2012 by edrach

[Fairtax4me]

There may be a way around that, I'll have a look at the wire diagram when I get home later. What year is your car?

 

There's no real reason to have DRL's in the U.S. They aren't mandatory, though most cars are available with them.

Making them work could be done, but I would worry about what might happen to the resistor with the higher amp bulbs in the circuit. It's designed to work with 55w bulbs, which would mean about 4A at 13.5V. With an 80W bulb, all of a sudden you have closer to 6A. And with 2 bulbs that means 4 extra amps, which means a LOT of extra heat that resistor might not be able to deal with. (The amp flow with the DRLs on is actually going to rely on the value of the resistor, it won't be an extra 4 amps, but either way it's going to be more.)

 

I'd just leave the resistor out and the DRL's disabled.

Edited October 15, 2012 by Fairtax4me

[FleaDog]

Measure the voltage on low side and high side relative to ground--should be pretty close the same (around 13V). If low side is significantly lower there's a problem; mis-wire, faulty relay contact. The other possibility I can think of is that on high beam, BOTH filaments are lit; on low beam only one filament is lit.

 

one light isnt going out if thats what you mean, they are both on.

[edrach]

There may be a way around that, I'll have a look at the wire diagram when I get home later. What year is your car?

 

There's no real reason to have DRL's in the U.S. They aren't mandatory, though most cars are available with them.

Making them work could be done, but I would worry about what might happen to the resistor with the higher amp bulbs in the circuit. It's designed to work with 55w bulbs, which would mean about 4A at 13.5V. With an 80W bulb, all of a sudden you have closer to 6A. And with 2 bulbs that means 4 extra amps, which means a LOT of extra heat that resistor might not be able to deal with. (The amp flow with the DRLs on is actually going to rely on the value of the resistor, it won't be an extra 4 amps, but either way it's going to be more.)

 

I'd just leave the resistor out and the DRL's disabled.

I had planned to leave out the daytime running light feature. Resistor was disconnected for just the reason you mentioned altho I didn't calculate the actual current. It's a 2002 Impreza OBS wagon. Thanks for the reply.

 

I was thinking of getting the DRL feature back by running it through the foglamps (55W each). I think I can diode isolate the wiring so the fog lights still work. But I'm not averse to having someone smarter than I help out. I can send you the wiring diagram from the FSM if you drop me an email by PM if you like.

Edited October 15, 2012 by edrach

[FleaDog]

Re: my light output issues:

dan stern emailed me back saying:

"You've got the wires swapped to the left and right vertical prongs of the headlight bulbs. This operates the high beams normally but puts the low and high beam filaments in series when you switch to low beam. Swap the left and right wires, leave the top horizontal wire where it is, and the problem should go away."

[FleaDog]

OK i think i got it sorted out, i mixed-up the pins on the bulbs.

 

Correct when looking at the back/base for all H4 bulbs afaik (not looking at the pin socket/stock harness): top horizontal pin is low beam, left vertical is common, right vertical is high beam.

[Fairtax4me]

OK i think i got it sorted out, i mixed-up the pins on the bulbs.

 

Correct when looking at the back/base for all H4 bulbs afaik (not looking at the pin socket/stock harness): top horizontal pin is low beam, left vertical is common, right vertical is high beam.

 

Good to know. Thanks for posting the pinout.

[FleaDog]

looking at bulb:

 

 

Looking at socket: