2004 Jeep Grand Cherokee radio

CHUCK1961

MEMBER
2004 JEEP GRAND CHEROKEE
4.0L
6 CYL
4WD
AUTOMATIC
145,000 MILES

After I bought jeep used the battery started to die, changed starter and alt. And replaced the battery at this time the jeep had a factory radio with cd changer in rear and amp under back seat. Battery still goes dead. Sent it to a mechanic to check the problem he traced it to the radio he removed the two fuses and the battery stayed charged. Figured problem was in the factory radio had an aftermarket radio professionally installed after three days the battery drained I pulled the fuses and charged the battery no drain as long as radio is unfused the aftermarket radio eliminated the cd changer in the rear so I removed it from the vehicle any ideas I can check without paying jeep dealer 95 dollars an hour to look for the short

1 Reply

CARADIODOC

MECHANIC
33,754 POSTS

You overlooked the most likely suspect, that's the remote amplifier. It is connected to 12 volts all the time, but gets a turn-on signal from the radio. Usually when the radio and ignition switch are on, 12 volts comes out of the radio on the "power antenna" terminal which is also used for the amp and cd changer. Most of the time the radio turns on a relay, and the relay sends current to the amp to tell it to turn on. I'd start by removing that relay. If the contacts are arced or pitted, they can stick on after the radio is off.

If that doesn't work or there is no separate relay, remove the fuse for the amplifier. I've only run into one bad amp since 1990, and that one is in one of my cars, and it failed to turn on. Due to the circuitry, I can see how it could prevent the amp from turning off.