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I have ruled out fuses and relays in the under hood fuse box, all good so I am hoping one of you learned gentleman can help before I start chasing the wiring harness. Everything else seems to work normally. When I pull the fuse for the DS or PS headlight the PS goes out. I am thinking that this might be a switch problem or perhaps a junction with the under steering wheel fuse box. Hoping you can point me in the right direction because this is vexing me quite substantially.
Fuses all good as are relays. Just checked and with low beams on I am getting no power at the fuse for the DS lowbeam but w/ highbeams 12V. Why no power at the fuse with low beam? Pass side lowbeam is fine and everything works normally…….High beams work normally…….totally stock…
You're going to have to start electrically troubleshooting to figure this out unless you can find some physical damage. Power at the fuse should remain constant with low/high beams. It is only controlled by the relay which turns on when the switch is appropriately set. Where did you have your negative probe when you measured that?
Driver side low beam no power 2001 Civic EX 
