Installed new bulbs (9004) for 87 300 zx headlights,,,,only get high beams no low beems at all...how to fix?

Most total headlight failures are caused by a bad component like a fuse, relay, or module. Wiring problems can also cause both headlights to stop working. High beam headlights don't work or low beams don't work. If just one bulb fails to work in either high beam mode or low beam mode, it may be the bulb. Check your manual to find your headlamp relay.

Check to make sure the fuse is not blown. The fuse for the low beam and high beam headlights are in the fuse block under the hood. Each light has its own fuse.

there should be a relay for the high beems have you checked this might be daft are the bulbs ok

someone has switched the wiring harness sockets to the wrong bulbs or installed the bulbs in reverse. get in behind the headlight assembly on the driver side and reverse the wires, if that does not work then pull the bulbs and swap them inside to outside and vice versa.

There is a good chance the low beam side of headlamp bulbs are both bad,I have seen this happen a few times.

Look under the hood.
There is a large relay which should have some info about lights on it.
I had this exact problem with my dodge ram

It's the dimmer switch in the column.

Hi my name is Allen!

The most probable cause is the multifunction switch. But I would try replacing one of the bulbs first to see if your low beems on the headlights or both bad. I have seen this several times. If the bulbs are OK the most likely fix would be the switch.

For further asistance you may reach me at FixYa!

check the continuity of the headlights to make sure there switching from the DTR Lights to the highbeams. If you are not getting the proper continuity check the ground wire for the low beams to ensure its properly grounded and has proper continuity throughout the wire. If not replace the wire or tighten as required and that should fix your problem.


lemme know if you require further assistance,

thanks - Nate

check your head light switch