help having many problems

[240sx unexperence god]

i have two problems. my dash lights, my digital speedmonitor, and my heads up unit, is not working, i was told it was a little white box, to the left, right by the floor/door. number 2. in fifth gear at 3500 rpms it kills out until it gets to 3000 rpms and then it kicks back up, and in fourth it waits until 4500 until killing out. it kicks back on at 3000 like in fifth. what could it be. please help

[Striker65]

Check your MAF (Mass Air Flow sensor) I had a similar problem with mine. It's probably just a bad sensor, try getting it cleaned, or just flat out replace it. It's about a 50 dollar part.

[joew921]

well the whole no radio and things like that im having the same problem my head unit my door chime interior lights wont work and my auto seat belts wont work unless i have the key turned to the on pos but the cutting off thing is your check engine light on ?

[chouyoukingdom]

i think is electrical work...u probably wire somethang wrong