Headlight relay (help!)

[monkeymajik]

I need a guide or some simple step-by-step instructions for wiring up some headlight relays for better light output on my ae86.

Aparently they are negative switching.

anyhelp would be muchly appreciated.

[maurice c]

First of all you need to see how much voltage drop you are getting from your old harness. Using the same earthing point first of all get a voltage reading with the lights on at the positive terminal and then at the headlight positive, Any less then a volt of difference between the two and you'll probly not get a lot of improvement with a heavy duty harness.

In case your thinking of running a high wattage bulb like 130/90 h4 or the like you better have metal and glass headlghts or your in trouble, they will melt with the heat.

You'll need a relay, some 25amp wiring form Jaycar and some suitable connectors. I've wired up my high beam inners on my 40 but it's all the same. You'll need to strip the old wires form the H4 holder , the positive and the negative. Run power directly from the battery to the relay, use the old 12v from the harness as a switch fo the relays coil and earth the other side of the coil, then run the power straight to the h4 positive, then earth the h4 earth straight back to the battery negative. Theres heaps of sites about that teach you to use a relay, I like to use quenching diodes on them, their pretty easy to find out about as well though, Good Luck.

[jonra23]

Hi
You will need to run 3 relays if you want to run relays for both high and low beam.

1 to switch the positive circuit (switches lights on and off)

1 to switch earth for high beam.

1 to switch earth for low beam.

If you dont run the power supply for earth switching relays from power switching relay they will drain battery when parked.


regards
jon

[bansheebuzz]

here is the correct wiring diag using 2 relays so that high beam indicator will remain functional

[jonra23]

here is the correct wiring diag using 2 relays so that high beam indicator will remain functional

Am a little puzzled why you have the original LB wire connected to the the 87a terminal of the C/O relay.

regards
jon


Just checked, to run High beam light, OK.

[bansheebuzz]

to make the high beam warning light function