Alright so I bought my 89 firebird right before winter and the headunit didnt work. So I tried multiple times to rewire it but nothing happened then i relized the fuse was blown so i replaced that. I also figured out soon after that the headunit needs a special fuse so i just bought a new headunit. The new headunit is a dual and when i hooked everything up it didnt work. The guy i bought it from claims the radio worked until a couple days before i came to get it. it has all upgraded speakers and everything and the fuse has been replaced multiple times. I have no idea what is wrong with it any ideas are greatly apreaciated. Also the batery has had a problem with keeping a charge it lasts about a week before it drains and i drive it maybe once a week.

 

For the head unit, you need a Voltmeter, or at least a test light. Pull the radio out, turn the ignition on, and test the Orange and Yellow wires for Voltage.

Orange should have 12V even with the key off, but yellow should only have 12V when the key is turned on.

If you have 12V on both wires, you might have a bad ground wire.

If you don't have 12V on one of the wires, you'll need to trace it back to where it loses voltage, either at the fuse block (for the orange) or the ignition switch (for the yellow)


As for the dying battery, you could have a ground issue somewhere, leaking +12V to ground. There could possibly be an accessory that's powered even with the ignition off (aftermarket amp, etc) that the previous owner had a manual switch hidden for. Ground faults are tough to track down sometimes, especially if it's on a component that you don't even know exists. In my last truck, the PO had wired in a small 80W amplifier under the hood of all places, run directly to the battery, and there was a toggle switch under the dash to turn it off. It took me a few days to track that one down, and remove it. :/


Best of luck, and report your findings with the meter/test light.

 

If you wanna check to see if the radio is good that you bought take the yellow and red wire and put them together and touch them to the pos end of the batt and the black the the ground it should turn on if not then the head unit is no good.


As for the batt like stated above sounds like a ground wire that is going bad or the alt is bad