I have a 1992 2+2 300zx and my high beams are stuck on. I tried replacing the relay for the high beams but it didnt help. Im out of ideas. Does anyone know what could be the problem here?

Have you checked/replaced the clearance illumination fuse? Located on driver side panel fuse box near the dead pedal. Another thing to check out would be the headlight switch itself mine went in my 93 n/a and after I replaced that it was good to go.... Also, which relay exactly did you replace? Could be a short too, the way it is setup is so if your haulin a** down the street at night, and the fuse blows or whatever your lights just don't take a crap on you, the highbeems will kick in and stay on until the short or fuse is replaced/fixed.. also i'd run the diag, test see if it shoots back any codes if the above advice fails to work.. Good luck!

ecu diag:
http://www.ttzd.com/tech/diagnostictech.…

I replaced the H/Lamp Dim relay. Didn't change anything. Ill look into the illumination fuse.

Changed my illumination fuse and that fixed it. thanks!

Just changed my illumination fuse and it fixed mine as well. Could barely see that it was blown.