Hoping I might get some help or suggestions. I have a '76 Trans Am, 455, 4 speed that is mostly original. My dad bought the car brand new.
I have searched and tried everything that I found. The short story is that the dash lights (gauge lights, heater control light) do not work. Everything else works....gauges, blinkers, cigarette lighter, radio, rear defrost, dome light, floor lights, glove box light etc.. I checked the small 4 amp fuse and put a new one in just in case. I tested the lights by using a 12 volt battery and running wires to the circuit board and they worked, so the bulbs dont seem to be the issue
The long story is that the speedometer cable was broken and I wanted to replace the 1980s Cobra radio/8t track unit that my dad had put in when the 8 track player stopped working. While I was at it, I decided to replace the dash bulbs. I also wanted to get the original 8 track working so I had it converted to work with a modern radio. I installed a USA-230 radio, connected to constant power via the orange lighter wire. I found a 12 volt wire that was running to the old plug for the 8 track player so I used this for the ignition power to the radio. I hooked the new 8 track power to the accessory tab on the fuse panel. Both the radio and 8 track work perfectly. Other issues were that for as long as I could remember, the oil/water temp gauge did not work. I installed new senders, made sure they were connected and replaced the dash printed circuit board. Both senders are working now. I also replaced the speedometer cable and changed the speedo gear successfully. Upon putting everything back together, I found that the dash bulbs were not lighting. I replaced the headlight switch, thinking the old one might be at fault, but they still dont work. I have a wiring diagram that shows all of the lights that are not working are the same colored (gray) wire. This wire runs to the direction signal and hazard switch connector as well. The gray wire is powered from the small 4 amp fuse marked instrument lamps on the fuse box.
I have been a backyard mechanic for 20 years or so but Im not the most experienced with automotive electrical. I am thinking that I have to check and ensure that the gray wire is getting power from the fuse box and making sure its carrying it to the circuit board and other bulbs. Is this correct? Do I just use a test light, probe the wire and attempt to find where its losing power? Is there a way to see if power is at the fuse?
Any suggestions or ideas of things to check would be really appreciated. Im just confused as to why they worked before I did the rest of the work, and they dont now. As far as I know, I did not mess with any of that wiring.
I have searched and tried everything that I found. The short story is that the dash lights (gauge lights, heater control light) do not work. Everything else works....gauges, blinkers, cigarette lighter, radio, rear defrost, dome light, floor lights, glove box light etc.. I checked the small 4 amp fuse and put a new one in just in case. I tested the lights by using a 12 volt battery and running wires to the circuit board and they worked, so the bulbs dont seem to be the issue
The long story is that the speedometer cable was broken and I wanted to replace the 1980s Cobra radio/8t track unit that my dad had put in when the 8 track player stopped working. While I was at it, I decided to replace the dash bulbs. I also wanted to get the original 8 track working so I had it converted to work with a modern radio. I installed a USA-230 radio, connected to constant power via the orange lighter wire. I found a 12 volt wire that was running to the old plug for the 8 track player so I used this for the ignition power to the radio. I hooked the new 8 track power to the accessory tab on the fuse panel. Both the radio and 8 track work perfectly. Other issues were that for as long as I could remember, the oil/water temp gauge did not work. I installed new senders, made sure they were connected and replaced the dash printed circuit board. Both senders are working now. I also replaced the speedometer cable and changed the speedo gear successfully. Upon putting everything back together, I found that the dash bulbs were not lighting. I replaced the headlight switch, thinking the old one might be at fault, but they still dont work. I have a wiring diagram that shows all of the lights that are not working are the same colored (gray) wire. This wire runs to the direction signal and hazard switch connector as well. The gray wire is powered from the small 4 amp fuse marked instrument lamps on the fuse box.
I have been a backyard mechanic for 20 years or so but Im not the most experienced with automotive electrical. I am thinking that I have to check and ensure that the gray wire is getting power from the fuse box and making sure its carrying it to the circuit board and other bulbs. Is this correct? Do I just use a test light, probe the wire and attempt to find where its losing power? Is there a way to see if power is at the fuse?
Any suggestions or ideas of things to check would be really appreciated. Im just confused as to why they worked before I did the rest of the work, and they dont now. As far as I know, I did not mess with any of that wiring.