JBL MBB2020 Troubleshooting Manual

Also see for MBB2020: Operation manual

1.0. Wiring Follow the wiring diagram above.• The red ACC wire is designed as the trigger to turn the radio on. It recommended that this wire is connected to anon/off switch for purposes of lowering the current draw on the battery while the radio is not in use.• Both red ACC and yellow battery wires must be connected to 12V+ for the radio to turn on.• Ground (black) must be connected to a good 12V- source. Best source is directly to the battery.• Speaker wires must be installed to the individual speaker’s terminals as labeled, positive and negative, respectively.Do NOT combine any speaker wires as this will cause permanent damage to the radio’s output IC. Tape off any unusedspeaker wires individually to prevent accidental shorting which can also harm the output IC.• Antenna must be installed.2.0 Compatible Accessories: See our website for the following add on accessories SEAMINI2 SEAUSBMINI JBL MC-20 MIL REM-50 MIL-RF9 Any antenna Any amplifier Note: can support: 1 two channel amplifier and subwoofer1 four channel amplifier3.0. List of common issues3.1 No Power• Check each button on the control pad for sticking. Under normal conditions, a faint click is heard upon pressing eachbutton. If any button does not click, initiate a warranty claim if you are under warranty.• Ensure red and yellow leads are connected to a good 12V+ source. Both must have power for the radio to turn on.• Ensure black ground wire is connected to a good reliable ground source.• Open the fuse holder and check the fuse. Note, while in most situations, a bad fuse can be spotted visually, this maynot always be the case. The best method would be to use a multi-meter or a test light.• Ensure the battery/power supply is putting out at least 12V while under load. The radio requires at least 11V tooperate normally.• Check all connections for corrosion, looseness, or other condition that can produce a bad ground. Corrosion orterminal looseness is the leading cause for most grounding issues and can cause excessive heat resulting in meltingwires or terminals.• If possible, connect the radio power directly to a 12V system, bypassing any toggle switches. If radio worksconnected directly to power, the problem might be with the toggle switch.• If the above doesn’t help, initiate a warranty claim if you are within warranty.3.2 Intermittent Power3.2.1 Powers on and off constantly Check voltage under load. At least 11V must be maintained consistently to operate the radio normally. If voltage cannot be maintained, load test the battery or power supply. Check all connections for corrosion, looseness, or other condition that can produce a bad ground.3.2.2 Powers off and on while vehicle is moving• Inspect all connections including the radio’s harness for looseness. Fasten down loose wires respectively. Wiggle connections while the radio is operating to produce the symptom and narrow down the loose connection. Ifradio cuts in and out while wiggling the wires on the radio side of the wire harness, initiate warranty claim.