1966 520 Headlight Relays

[jay520]

So, my truck didn't have a light relay in it when I got it. I was hoping to do the two relay install, but my wires are a bit different than the ones I've read about on here. It doesn't seem like there are enough wires running from the switches to connect both relays. Perhaps somebody out there can help. This is what it is set up like now:

 

 

 

 

Here's what I'm thinking. The RB and RW go to the 87s. The 85s are grounds. 30s are a feed from the battery with an inline fuse. But what goes to the 86s? Other people that have done it have the RY going to one and a B/R going to the other, but I have no B/R. That's why it seems like I don't have enough wires. Am I not going to be able to do it then?

[boxboy]

Try looking at this thread? http://community.ratsun.net/topic/22271-head-light-problems/ I didn't have a headlight relay either when I bought my '68. Someone had just wired it direct to get the low beams to work and I had no highs. I think you can figure it out with Mklotz's directions. I just had the wrong relay when I initially set this up. Now I have it working great with Mklotz direction.

 

Good luck.

[jay520]

I've looked at that, that's where I was getting most of my info on doing this. I guess I'm trying to figure out what the trigger wire is for the hi beams. I don't have a B/R like the wiring diagram shows, since I don't have a column switch. I have a floor switch, and there doesn't seem to be a trigger wire coming out of it.

 

 

Boxboy, this is how yours is set up, right?

 

Relay #1:

 

30--Power from an open slot from a 30a fuse "lights" in the fuse box. (this is the same as running power from an inline fused feed from the battery)

 

85--ground to fender

86--RY wire from the dash switch

87--RB wire to the low beam lights

87-- open (this is now 87a, since you've replaced the relay)

 

Relay #2

 

30--Power from a fused line from the pos. batt. term.

85--BR wire from the column switch (this is what I'm missing, does the RW from the hi-beams switch act as the trigger on my truck, by any chance?)

 

86--RY wire from the dash switch

87--RW wire to the high beams

87--open (also 87a, now)

 

I was also under the assumption that 85s are grounds,86s are triggers, 30s are feeds, 87s are normally open contacts to the lights, and 87a's are normally closed contacts that don't go to anything (allowing the lights to be off if the relay isn't triggered).

 

Also, does the Relay #2 not need to be grounded?

[boxboy]

Not able to take a look just now, but on mine, what the column switch does is actually ground that relay which turns on the high beams. Kind of weird, but it is grounding it that actuates it, not power. I don't know how the foot switches are wired. You should be able to trace a wire from it somehow.

 

Also, doing it the way I did, the goal is getting the power away from the fuse block as Mklotz said. So I ran a fuseable link to the battery. No interference then with other fuses and switches.

[jay520]

That makes sense. Since the RY is carrying power to the second relay as long as the low beams are on, you need to be able to use the relay to switch that.

 

Thinking more about it. I'm thinking (probably way off, but let's see) I would splice a wire into the RY that runs from the light switch to the hi beam switch and run that to both 86. RW (because what else could the trigger wire for high beams be?) from the hi beams switch to the 85 on the second relay. Then everything else the same as what is written above.

 

The RY running between the switches is carrying all the power from the first switch to the second. Then on the foot switch there is a normally closed circuit running to the RB wire and out to the low beams. And then when you hit the foot switch it closes both circuits (RW and RB) or would it just switch the power to the RW and that becames the closed circuit and the RB becomes open? Basically, when hi beams are on is there still power running through the RB (lo beams) wire? Or, does power only run through the RW when the hi beams are on?

[boxboy]

I couldn't tell you. I have four headlights, and they all come on when I hit the brites.

[jay520]

It's cool.

 

Looking at a 320 wiring diagram, I've come to the realization that my truck is set-up more like the 320s rather than later 520s, as far as the headlights go (the 320s have a dimmer switch with the same color wires coming out). So, I'm thinking there was never a light relay to begin with. I guess now I'm trying to figure out why the headlights don't work (I was hoping someone had cut the relay out and did a shitty job putting the wires back together), and if there is a way to do this two relay thing.