Expert: Cleggsan - 2/23/2010

Question
Hi, I installed a Phase Linear/Jensen/Audiovox UMP301 in a 1983 Chevy truck. I have discovered that it constantly draws .5 amp through its memory wire to maintain the station settings etc. This draw causes the battery to get real low in 1.5 days. Any idea what may cause this? Is it an easy/cheap fix? Its an inexpensive CD/receiver so...I have verified all the wiring, it's correct.
Thanks

Answer
It is hard to believe this is the normal standby current draw.  Normally it is only a few milliamps.

Do you have the dc voltages wired correctly?  You say you are sure, but if the two 12v lines were reversed it could cause this.  There is one 12v line that is permanently connected; it comes directly from the battery (probably through a fuse) that keeps the memory stored, etc.  The other 12v line is the remote turn on and it comes from the ignition.  When the unit is turned on it will light up the panel and turn on the amplifiers.  If the amps were left on it could cause this excess draw.

You did not give the truck model but the only wiring chart for that year that came up easily is a  1983 S10 pickup.  Check the wiring against what your wiring diagram and see if there is a discrepancy.

If it is not the wiring.....  it is likely a defective unit?

Your unit is YELLOW for constant 12v - goes to orange in the vehicle.
and RED is the ignition color - which connects to yellow in the vehicle (switched wire).

For example......

Hope this helps.