Thank you, doing my best half blind. I would start at the relay under the dash. That bypasses the switch and has an always hot feed to power the headlights. If you look at the schematic goto terminal 30 at that relay. If there is no power there. You will have to work back to the fuse box to the always hot side which is fed from the power distribution. Looks like fuse six and seven. The left side of the fuses.
Now turn on the headlights with the key on. You should have power at the terminal 87 on the relay under the dash. If you don't then troubleshoot the headlight switch and power to the relay from the headlight switch. The headlight switch turns on the relay at terminal 86 where you should measure power with the switch on and ground for that is terminal 85. Make sure that ground is good because no headlights.
If terminal 86 has no power then the headlight switch or the feed to it has problems. The headlight switch gets switched power from fuse 1.
I would always start to troubleshoot at the under dash relay since that provides power for both high and low beams to the step relay when the lights are turned on. Looks like the yellow in the diagram.
You can check all this with a test light.
You can also check the step relay function by sticking the probe for the test light in terminal 31b looks like a brown wire marked BN which could also be black. lol. The one coming from the turn signal lever. It grounds the step function side to change from high to low beam and putting the probe in there gives the relay the ground through the light bulb in a test light.
Hope that is a bit more helpful.
Dave, thank you for taking the time to write those detailed instructions. This has been the first time I didn't feel completely overwhelmed--especially when wondering what point to start with.
Thank you also for making me love the test light, which I think many people don't realize how useful it is. This included myself, until you described in layman's terms what to do with it. At first, I thought it was a shorted wire, but the test light illuminated on the green/red and white/blue wires--even when being jostled.
Despite hearing the relay engage, I must say, you were right! I tapped on the top of the relay and the lights would momentarily come on indicating a faulty relay.
Speaking of relays, which replacement do you recommend?
While the numbers are the same, the schematics on the relays look different. I was unsure if they could be interchangeable, that, and there is a considerable price difference.
https://www.eeuroparts.com/Parts/7294/Relay-Window-1235893/
and this one:
http://www.rockauto.com/en/moreinfo.php?pk=3784935&cc=1287053&jsn=446
I think that I will test the remainder of the switches and the high/low beam relay which you suggested to make sure everything is in working order.
Thank you again Dave, for your spot on troubleshooting. It feels much better after taking that first step with the test light!