Headlight conversion wiring advice (1 Viewer)

[Izeloz]

I just got some new headlights from eBay and they use an H4/H1 bulb combo rather than the stock 9005/9006 combo. I figured since I had to do some rewiring that I would add some relays and clean up the wiring a bit. My question is this; the H4 uses three terminals, a high beam, a low beam, and a common. The 9005 and 9006 only have two terminals each. My cruiser has four colors of wiring in the stock harness; black/white, red/white, red/yellow, and red/blue. The red and blue are common to both bulbs on the passenger side and the red and white are common to both bulbs on the driver side. The red and yellow only go to the 9005 (high beams) and the black and white only go to the low beams. Which of these would I use for high, which for low, and which for common? This is on a '92 FJ80. I would post the stock wiring diagram but I don't want to get in trouble for copyright violation stuff. Can anyone help me? Thank you. I am using the attached schematic to wire up the new lights.

 

[Izeloz]

bump for the weekend

 

[robmir]

I just got some new headlights from eBay and they use an H4/H1 bulb combo rather than the stock 9005/9006 combo. I figured since I had to do some rewiring that I would add some relays and clean up the wiring a bit. My question is this; the H4 uses three terminals, a high beam, a low beam, and a common. The 9005 and 9006 only have two terminals each. My cruiser has four colors of wiring in the stock harness; black/white, red/white, red/yellow, and red/blue. The red and blue are common to both bulbs on the passenger side and the red and white are common to both bulbs on the driver side. The red and yellow only go to the 9005 (high beams) and the black and white only go to the low beams. Which of these would I use for high, which for low, and which for common? This is on a '92 FJ80. I would post the stock wiring diagram but I don't want to get in trouble for copyright violation stuff. Can anyone help me? Thank you. I am using the attached schematic to wire up the new lights.

Of course your H4 high beam will work at the same time as the H1 high beam meaning that the red/yellow will be the one to provide the turn on signal to your upgraded relay / harness combination feeding the H4 high beam filament in parallel with the H1 high beam.


You will use the black/white to provide the required signal for the lows.

Your high beam combo will draw double current so take this in mind when sizing both positive and ground wires. The digram you showed is well rated but use dielectric grease to protect the relays sockets and the relays should be the sealed type.

I sugest you to source the best quality socket to plug the H4 bulb.

The headlamp setup you got is the E type which is way better than the DOT and you have a wider choice of bulbs.

On mine I use Hella bulbs been the H4 55W/100W and the H1 100W.

 

[Izeloz]

Yeah, I used at LEAST 12 gauge for everything in the entire harness, 10 gauge for the ground and power feeds, and weatherpack connectors throughout. I got a high temp., high wattage socket for the H4's from a local parts store. So you're saying the red/yellow will be my high signal, the white/black will be my low signal and the other (red/blue, red/white) will be the common? Thanks for your help.

 

[treerootCO]

H4 pinout looking at the rear of the bulb, middle pin on top:

Left - Gnd
Right - High Beam
Top - Low Beam

Here is a writeup for converting 9005/9006 to H1/H4
https://forum.ih8mud.com/80-series-tech/231171-h4-h1-headlight-conversion.html#post3485348

 

[Izeloz]

Thanks. I already have these wired and they are working well. I used the wiring diagram at the top of this thread. After a bit of head scratching I got everything worked out. I am thinking of converting my H1 bulbs back to 9005's, though. I'm not too fond of the H1 connector. Seems more prone to rattling loose than the H4 or the original 9005s.