so i have an 85 z31 n/a digital dash. and the dash and radio all of sudden has stoped working right. like when i first start the car the dash will not turn on. but if i rev it a bit, it turns right back on. same with the radio. the turn signals all blink super duper fast and even faster when the car is moving. the battery seems to be charging almost at 16 volts! when i get the brake pedal everything turns off and turns back on real fast. example. the radio and dash will turn off but only the dash will turn back on. i have to turn on the radio manually and this happens everything i hit the brakes. there is also a small buzzing sound coming from where i believe is behind the radio when i hit the brake pedal. the dash powersupply looks fine and does not show any damage. help plz? thanks

 

Replace the alternator, get back to us.

 

get your battery load tested and the charging system also. free most battery shops. are your battery cables in excellent shape. terminals tight with no corrosion - both ends. is the ground strap grounded to the frame before it goes to the starter. grounding through the starter is not a reliable method. IF your battery cables have those one size fit all clamp type connectors get rid of them get some real battery cables those jackleg fitalls that lazy people use are problem waiting to happen. pic of terminal i'm talking about.

 

yeah terminals and everything are great. ill got get the battery tested and alternator. thanks

 

so i finally got the battery and the alternator tested. so i the alternator was bad so i changed it. everything started working! then i turned on the head lights and everything stopped working like the radio, dash lights, turn signals, and even that bell sound when you open the door. except the headlights and high beams. that still worked, oh and brake lights. no idea what it could be now...... i might need to go get it all tested again. any idea what it could be?

 

Fuse.

 

like he said fuse....check ALL your fuses....i had the same problem and it was a simple fuse.

 

any idea which fuses i should replace or how to diagnose it? atm its the dash, brake, signal, radio, clock, door bell sound when you open door, interior lights, everything except the headlights. when i do rave the car a bit the red light for the battery on the dash does light up but thats about it.

 

kinda sounds like the new alternator smoked if you are seeing a red light on the dash.

 

i jumped the car and everything worked fine for a bit. seems like the battery isnt getting a charge. everything turned back off again once i parked the car. ill get the battery and alt tested again and see from there. its not a fuse tho. its just not getting a charge it seems.

 

well changed the battery. everything works fine now...........