2004 hyundai accent, not enough power

I'm trying to install a cd player into my 2004 hyundai accent, but i can't get enough power. The radio doesn't work when the car is in accessory mode, but the radio will play when the engine is running. The cd player won't work under either scenario.

There is a voltage drop from 13.8 v down to about 8.4 v when i try to turn on the radio (with the engine off). After the voltage drops, the radio turns off and the votage comes back up. Then the radio turns on and the voltage drops, and so on. It's about a 5 - 7 second cycle.

The same thing happens with the engine on if I try to play a cd.

What can I do?

Probably not. I pulled the cd player out of my old car, where it worked just fine. After my first attempt at the new car, I put it back into the old car, and it worked fine again. I'm kinda stuck. The factory tape deck works in the new car & the cd player works in the old car.

Check your fuse.  It maybe to weak to keep supplying your radio with juice but to strong to blow when loaded.

some Hyundais used common ground speaker wiring, which your HU will see as a short, whereas your old vehicle may have used isolated wiring, grab a meter and verify for any commons to each other or to chassis.....

try just hooking up power ( & ground obviously ) and connect one speaker out to a test speaker, does it work fine?

Kevin,

I havn't connected the speakers yet. This problem is happening with the ground, always hot, and ignition hot connected only.

do toy have access to a meter?  use it as an ammeter and see what kind of current is being drawn on first the constant and then the switched line.....

assuming you have tapped into the correct wires it's not logical for battery B+ to drop so low... what happens if you hooked this deck directly to the battery?  what happens if you twist Acc and B/U together and go to one or the other... i suspect a faulty circuit somewhere or something is hooked up wrong

go direct to the battery and see what happens first... there shouldnt be any difference in doing this or doing it at the radio harness....

do you have access to a meter?  use it as an ammeter and see what kind of current is being drawn on first the constant and then the switched line.....

assuming you have tapped into the correct wires it's not logical for battery B+ to drop so low... what happens if you hooked this deck directly to the battery?  what happens if you twist Acc and B/U together and go to one or the other... i suspect a faulty circuit somewhere or something is hooked up wrong

go direct to the battery and see what happens first... there shouldnt be any difference in doing this or doing it at the radio harness....

Thanks guys,

The "wire directly to the battery suggestion" was the fix. It worked fine in that scenario. So I'm bringing in a direct wire from the batery to the cd player. It seems that the stock wiring wasn't of a thick enough gauge.