Apologies for the delay; having completely rewired my car I wanted to get it started, running, and totally functional before sending anyone off on a wild goose chase with bad directions. I’m afraid I don’t take many pictures while working on the car so I can’t provide those, but I thought a short tutorial might help people add headlight relays to ‘67s with the factory RS setup.
1. Parts: I used Hella weatherproof relays (Waytek # 75605) with Hella weatherproof relay connector/harnesses (Waytek # 75610) as well as a Type 1 circuit breaker (Waytek # 46430). Pretty high-quality parts although there’s nothing inherently special about them and any equivalent relay would be fine. I also hate butt splices whenever they can be avoided so I tried to make fresh connections with Delphi Packard 56-series crimp connectors every time possible. I crimp, solder, and heat-shrink each under-hood connection given the heat, vibration, and moisture. Clearly, there are arguments to be made for not soldering (longterm risk of stress fractures in the conductor with vibration) but I’m a believer in soldering them anyways. To each his own.
2. Power source: My recommendation for this terminal would be to run a power lead directly from the main power distribution point on your vehicle (the horn relay if you have an old externally regulated alternator; I converted to an internally regulated alternator and have a BlueSea busbar on my radiator support but that may be overkill) with a Type 1 (self-resetting) circuit breaker in-line for each circuit (high and low beams).
3. Relay board modification: This is simpler than it looks. Pull your relay board out of your car and identify which relay is #1, 2, and 3 (http://retro-electro.net/FAQ67.html
has an explanation on how to identify them and the AAW directions for their RS wiring kit have a picture ID-ing each relay if in doubt). You will note two light blue wires going to one terminal on R1. Disconnect this and cut the connector off so the wires are loose. Then, take the light blue wire coming FROM the firewall (NOT the one going to the other relays) and combine it with the wire from terminal 85 on your new relay; connect them to the same terminal on R1 that you just removed the light blue wires from. You will now have a loose light blue wire leading to R3 and then onwards to R2. Take this loose end and connect it to terminal 30 on your relay (so terminal 30 is electrically continuous with the light blue wire terminals on R2 and R3). Now, connect terminals 87a and 86 on your relay to a good ground. Terminal 87 should be terminated – it does not need to be connected in this. You are now done with your relay board. Functionally, when no voltage is applied to the coil, the light blue wire from R2 and R3 is grounded through terminal 87a. When the light blue wire to R1 is energized, the coil is operated and the new relay disconnects the light blue terminals of R2 and R3 from ground (by connecting them to terminal 87, which is not hooked to anything). This solves the problem with the lack of a ground path through the light filaments after you add relays to the high and low beam circuits.
4. Headlight relays: You will perform the same task twice, once for the high beam circuit and once for the low. Identify the high beam and low beam wires from the firewall to your bulbs and cut them. Pick either highs or lows and take the end of wire coming from the firewall and connect it to terminal 85 on your relay. Connect terminal 86 on your relay to a good ground. This is your coil circuit (and actually, you could swap those terminals if you wanted to). Connect the cut end of the wire going to the bulb to terminal 87 on the relay. Then, connect terminal 30 to your power source. Then, terminate terminal 87a – you don’t use it on this relay. Repeat this sequence for the other (high or low) circuit.
That’s pretty much it. The rest is all just how to mount everything in the limited space available between the radiator, washer tank, etc. This setup worked well for me – with the addition of a set of H4 housings and bulbs from Susquehanna Motorsports, it’s massively brighter than stock. Can’t swear how much is due to the relays as I replaced the whole harness and converted to internally regulated alternator at the same time, but it’s theoretically a better system and definitely cuts back on the amperage running under-dash.