Headlight problems. Help Needed!
Reply #19 –
I like pics. I really, really do. :D
All power for the "normal" headlights (high and low) goes through the dimmer switch. "Flash to pass" is a separate circuit with a relay, that is activated by a set of contacts inside the dimmer switch.
In pic #1, the round contacts in the upper left are where the power goes through the dimmer. High beam is diagonal one way, low beam diagonal the other way. The 2 vertical tabs just below the pads are the contacts for "flash to pass", pushed by the plunger sticking out of the green block (the high-low toggler thingy).
The "rocker" switch in the lower left of pic #2 is what flips back and forth to give high- and low- beams. The "contact bar" is lightly spring-loaded, and rides in the plastic block, as seen in pic #3.
Over time, dirt and general corrosion contribute to a bad connection, which causes the contacts to heat up, often enough to melt the plastic block the contact bar is in. The block gets mushy, the bar is pushed into the mush, and it sticks there, creating an even worse connection. If it's particularly mushy at the time, the contact points can get coated with melted plastic, resulting in no contact in either position, and even a high-low switch that doesn't "click" any more.
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