Questioni have a 2000 dodge ram and i recently installed a cd player in it and then installed some subs but the problem is is when i unhooked the positve battery teminal the cd player will no longer come back on. when you unhook the wires from the back of the cd player it sends a poppin sound thru the speakers like its gettin power to the cd player it just wont come on. do you know what the problem might be? thanks
AnswerHi Andy,
Generally, if you're having a problem with a component that won't turn on at all, the best way to troubleshoot it is to use a digital multimeter.
Most after-market head units have two power wires; one red and one yellow. The yellow wire is a constant power connection, while the red wire carries key-switched power. The head unit won't switch on unless there's power on both wires, and a good chassis ground connection through the black ground wire.
In your truck, the factory ground would have either been a striped black wire, or a braided metal strap. Either way, it would have been connected directly to your factory radio's chassis, either with a ring terminal and bolt, or a spade terminal connection. Your after-market head unit's ground wire should be connected to this factory ground wire.
If you're certain the ground connection is good, you should test for voltage on the red and yellow power wires. Set the meter for DC volts; attach the black probe to the ground wire, and use the red probe to test the yellow and red wires. If the vehicle's key is on, both wires should test with around 12 volts. If both wires show voltage, and the head unit won't switch on, you probably have a defective head unit. If you find that one or the other wire doesn't have voltage, though, you should check the fuses in the vehicle fuse box. Each power wire has its own fuse, and they may not both be labeled as radio fuses; so you might need to check all the fuses. Be sure to check the fuse box in the engine compartment.
Hope this helps!
Brian
