Headlight relay Schematic

On the old site, there was several technical articles, which included how to add a relay to you headlight wiring. Does anyone know how to access that diagram? I have a pretty good idea, but I need to know which posts to use on the relay.

 

this is for a 4 headlight system would work the same in two just use the low beam wires on one relay and the high beams to the other...

 

Cool, that helps. I see that I need a second relay for the high beams.

 

And another...

 

There are dual relays available.

 

I would not bother with a dual relay. There's no difference between a dual relay and a pair of Bosch/Tyco-style relays, other than a second connection and two packages. The relays are available cheap from Parts Express http://www.parts-express.com/pe/showdetl.cfm?Partnumber=330-079

Not much to this other than getting the switch out of the circuit, and makin your power feed to the lights as short and as large qs possible. Note that running a dedicated ground from your lights will improve the brightness too. Big wires, short path, low resistance.

 

Just a comment - the 10ga ground to the relay (post 85) serves no purpose in this diagram. It's fine to ground the relay coil to the fender and delete the expensive 10ga ground wire, back to the battery. If you want a dedicated 10ga ground, it should go to the bulb ground instead of the relay coil ground. The relay coil (85 and 86) does nothing but energize the coil to switch the contacts, and is a low current circuit. No need for any heroic-sized wires here.

The relay diagram in this drawing is correct in terms of connection labels, but wrong pictorially. The diagram of the relay in sterlclan's post is correct. Use the headlight wires to energize the coil, and connect the big red wire to the switched contacts (30, and normally open 87).

A dedicated ground from the bulbs will help, but won't be as much of an improvement as the dedicated power wire to post 30 of the relays.

Also, if you use the existing headlight wires to the bulb, put the relays as close to the bulbs as practical. The idea is to connect the big power wire (big red wire) as directly to the bulb as you can. Big wires means low resistance, and more current to the bulbs.

 

You are correct sir! Good find Tim, thanks,

 

Yeah, I didn't run a separate ground for the relay. I thought that it would be a waste. I have already wired the relay for the headlights. I still need to do the brights and a ground wire for the headlights. Looks like I still have fabric insulation to the headlights that needs to be updated.