I am having trouble with the headlights on my '07 EL.

It started with the passenger side light going out. It was intermittent, so I figured it was about to go out and bought new bulbs. When I replaced that side I noticed the connector was rusty and corroded. I cleaned it out and put the bulb in. It worked fine for a few days then stopped working again. After another deep clean I decided to just replace the connector, I was only getting 8v on the low beam. Brand new connector and still the same issue, same voltage. I checked the fuses (each low beam has its own fuse) and found the fuse didn't look right, the tip was bent like it melted a little and got soft. So I replaced the fuse. Still no lights. I swapped the driver and passenger fuses and both headlights would not work. Then I started the truck and when it was running the driver side will come on. But now it's being intermittent. If I turn on the fog lights it will go off. If I turn off the fog lights it will come on for a second then go off again.

I cannot not find any mention of a low beam relay, or another fuse under the hood. High beam has been fine the whole time, and fog, and tail/turn. It's only the low beam that is giving me trouble.

I think this points to the actual headlight switch in the dash, but am hesitant to buy another part blind. Each step of the way I found an issue, and then tracked it back to another upstream issue. What else can I check before buying a new switch?

I hate electrical issues

 

Update: it's not the headlight switch. I replaced the switch and still have the same issue, but the drivers side lights seems to be fixed now.

Any other ideas?