'90-'94 Chevy Lumina Headlight System

[jimmbb]

Okay, I am now an expert on this subject. I came here looking for help, but found others with same problem. -No headlights/no running lights. Ended up paying an "expert" on "JustAnswer"! Thought I'd share:
First: There are three fuses/breakers to check. 1) The 10amp in the glovebox. 2) The 20amp in the "component block" under the glove box. 3) The 50amp in the "breaker box" under the hood on drivers side.
Second: If these are good, don't go running out buying parts like I did. (There may or may not be a Headlight Relay; it's listed and I bought one at a parts place, but my expert says there isn't one. Wasn't one on the schematic either, but when I was done and plugged in the breaker, I heard the distinct clack of a relay somewhere!) Check for 12v on the two Drk/GRN wires going in to the Lightswitch from the component center. Also; 12v on the pnk/blk wire form the Turnsignal (Dimmer) Switch via the glove box. (Don't be fooled by erroneous small voltage readings; this happens in cars; look for a good 12+volts.)
Third: Go from there: If you don't have 12v on the pnk/blk, it's probably the Turnsignal Swtch. (You have my sympathy!) If you don't have 12v on Drk/GRN.s, (Like in my case.), start tracing back through ComponentBlock to the BreakerBox. (I found a corroded wire just under the breaker-box on the wheel well.) Of course, if you have all three 12v.s, it's probably the Lightswitch.
Hope this helps somebody!

[maxwedge]

Good info, but the use of a shop manual and oe wiring diagram should have been sufficient to track this down.

[jimmbb]

That's nice. Just where do we lay our hands on a shop manual and whatever an OE is??? I've tried and only end up Yahoo at Repair Manuals where; for a price they'll send you one.

[maxwedge]

Correct, you have to buy one, what's the issue there? oe/ original equipment.