When I turn on headlights dash lights go out, when I turn headlights off dash lights come on, any ideas,,am new here

 

I would check the ground. I have no idea where it is on an Accord.

 

The ground to ?

 

Has this car been in an accident or any work done on the car recently?

I'd start with where the headlights ground to the body. This is going to be below the headlights on each side.

The diagram in the shop manual I have (thank redbull) is not clear if the bumper would need to be removed. I'd disconnect the battery. You will have to follow the wire harness near the headlights to where it branches with a several black wires to a bolt on the body.

Unbolt those grounds. Clean the eyelet and bolt with a wire brush or sandpaper. Then reattach. Clean the battery cable and posts while you are at it.

 

My wife is the driver of this car,I took it in to dealer for air bag recall, that was a couple weeks ago. While I was driving it I noticed this light problem. Well u can kick me in the butt for this but I was trying to adjust the dimmer with the drivers vent on off lever. That is where the dimmer switch is on any other car.Well I found a 2005 Honda manual and found out where the dimmer switch is and all is ok now. This is one of the best cars we have owned though. Just want to thank u for your time for my dumb ***