Relay cavalier low bean - 1988 Chevrolet Cavalier Z24

check fuses.
check head light relays.

yes low beams go off when using high beams on most cars and trucks

it can only be 2 things
1: bad combo switch (light switches in steering cluster)
2: bad wiring.
this assumes the car does not have DRL.
day light running lights.
i simple tool called a voltmeter finds this fault easy.
do yo have one?

Check dimmer switch, replace if needed,'

Check light sockets and wires, replace as needed.

Check for relay if applicable.

Someone will need to check for voltage at the dimmer switch and then trace back to the fuse box as needed.

I'm having the same issue passenger side low beam not working checked fuses an relays an the bulb what could it be

Replace Relay #46 in the underhood fuse panel.

a bad new bulb?????

If your car is running daytime running light system .. there is a DTR relay that goes defective and needs replacing ... I had the identical problem that was fixed with this replacement. The DTR relay is behind the glovebox.

I have a '96 toyota tacoma head light are fine, went to buy new ones but low bean still does not work on both. High beam works. Is this a problem with the relay.