Bad Contacts on dimmer-switch combo (stalk)
Got a multi-meter?
Nothing... my corner lights cut on but no headlights. and the blue high beam light is on
Bad Contacts on dimmer-switch combo (stalk).
This is why:
Red lines trace current flow while in High Beam
(First gen schematic here but I think second gen Runner headlight ckt works same way).
Control Concept:
When headlight relays come on 12V from headlight fuse go through low beam filaments, to terminal 1, to positive side of HB indicator (where all the
R-
G wires meet).
To turn on low beam, dimmer switch needs to connect one side of filament (terminal 1) to ground.
To turn on high beam, dimmer switch needs to connect term 2 to ground.
During normal operation:
Going to low beam grounds this point, turning high beam indicator off and since term1 is grounded Lo Beam turns on.
Going to high beam floats this point (term1 = pos side HB indicator = R-G wire), so 12V stays there, turning high beam indicator on. Since term2 is now grounded High Beam turns on.
Right now, on your rig:
"Blue high beam light is on", indicates that your dimmer switch is doing
neither of the above.
The problem with many earlier model wiring is that these flimsy contacts are carrying high load currents so they'll arc and eventually get pitted/oxidized from all the arcing. Pitting and/or oxidation leads to high resistance leading to heat, leading to more oxidation.
Stock wiring also means your power runs from battery, to bulbs back to cabin to dash, back to engine compartment to fender ground. Long wire= lots of resistance = less power actually getting to your bulbs.
After you fix the dimmer switch, I recommend you look into the H4 Upgrade harness. This will make power go directly from battery to bulbs back to fender ground - a shorter loop, and no load current on your dimmer switch.
).