R33 headlight relay conversion?

[joshuaho96]

I was poking through the R34 wiring diagrams vs R33 and noticed that the R34 has proper headlight relays while the R33 is like the R32 and sends full headlight power through the headlight switch. I'm not afraid of wiring but I really would like to do this in a way that looks OEM (clipping into open positions on the OEM relay box) and also unlike the factory wiring which interlocks the high beam and low beam on the halogen series 1 GTR headlights I want to make it such that turning on the high beams keeps the low beams on as well. Any advice on how to locate the specific connectors + crimp terminals + relays I need? I was thinking one NO relay for low beams and another for combined high + low running off the factory high beam headlight connector. I don't really want to splice into a crusty old probably discontinued factory harness so fully reversible is my goal here.

[GTSBoy]

Bugger "making it look stock".

I put one conventional internally fused Hella relay behind each globe. I just pulled the plugs off the back of the globes and built new loom segments with male and female plug parts to match up to the original loom and the globe, and used the original power wires to each globe coming from the switch through the original loom plug to trigger the relays. Ran a big fat (also separately fused) power wire across the front of the car to feed all the relays. It's as ugly as f**k, but it is wedged down between the headlight and battery on the RHS and the airbox and headlight on the LHS, and no-one ever looks in my engine bay, and on the odd occasion that they do I simply give no f**ks for what they think.

Fully reversible - not that you'd ever want to. For f**k's sake. It's a Skyline. They made million of the bloody things. We've been crashing them into roadside furniture for 30 years now.

There is a negative side effect to putting relays on the headlights. The coil current is too little to properly clean the contacts in the switches and they get blacked up and you have to open them up every couple of years and clean them manually. I have 25 years of experience on this point.

[joshuaho96]

3 hours ago, GTSBoy said:

Bugger "making it look stock".

I put one conventional internally fused Hella relay behind each globe. I just pulled the plugs off the back of the globes and built new loom segments with male and female plug parts to match up to the original loom and the globe, and used the original power wires to each globe coming from the switch through the original loom plug to trigger the relays. Ran a big fat (also separately fused) power wire across the front of the car to feed all the relays. It's as ugly as f**k, but it is wedged down between the headlight and battery on the RHS and the airbox and headlight on the LHS, and no-one ever looks in my engine bay, and on the odd occasion that they do I simply give no f**ks for what they think.

Fully reversible - not that you'd ever want to. For f**k's sake. It's a Skyline. They made million of the bloody things. We've been crashing them into roadside furniture for 30 years now.

There is a negative side effect to putting relays on the headlights. The coil current is too little to properly clean the contacts in the switches and they get blacked up and you have to open them up every couple of years and clean them manually. I have 25 years of experience on this point.

Hmm, how does the R34 manage to have headlight relays then without getting excessive carbon buildup on the headlight switch contacts?

[GTSBoy]

Any number of different ways.

• Have the coils draw sufficient current to provide contact wetting.
• Use different contacts in the switch, either by material or design, better suited to the low current drawn by a relay coil.
• Etc.

[Duncan]

I don't know what globes/headlight connector they run, but I'd be looking for a female adapter to plug into the existing headlight on one side. Something like this https://www.ebay.com.au/itm/256017245989

Then I'd use a pair of single input, double output relays (one for low, one for high), mount them in a spare space in the fuse box if you want to to look more original (and be easier to maintain). Then 2 new power sources from the main stud in the fuse box via a fuse to each relay. Low from the headlight adapter pin triggers low relay and high from the high headlight adapter pin triggers high and low. Earth the relays and new headlight sockets and off you go. Because it triggers off the original headlight all of the dipping/hi on/high flash all still works