JBL JBLMR18.3 User manual

JBLMR18.3 Troubleshooting Guide
Prospec Electronics
Note: Please click highlighted words for links to parts of this document and our website.
1Wiring
2Compatible Accessories
3List of common issues
3.1. No power
3.2. Intermittent Power
3.3. Buttons/controls not responding or behaving erratically
3.4. Poor reception or no reception
3.5. No audio, speaker audio is unevenly distributed or some speakers not working
3.6. Low audio
3.7. Fluctuating Audio
3.8 Moisture in Display
3.9 CD Player won’t play
3.10 CD door won’t close/open
4 External Amplifier Issues
5 Sirius Issues
6 Reset Procedure
7 Lubrication of Volume/Tuning Knobs
8 Location of Product/Serial Numbers

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 an
on/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 unused
speaker wires individually to prevent accidental shorting which can also harm the output IC.
•Antenna must be installed.
•Blue wire, labeled “AUTO ANT” is a remote wire for powered antennas/amplifiers/subwoofers.
•Rear/front line outputs are low level outputs with right/left and front/rear fade controls. This is for an output like an
amplifier or subwoofer.
•Remote control cable is a 13 pin DIN style cable designed for wired remotes (see compatible products on the next
page.
•AUX inputs are female RCA connectors for use with input devices. The stereo will NOT control any of these devices,
but they will be heard through the stereo.
•Sirius cable is designed for use with a Sirius Tuner (see next page).

2.0 Compatible Accessories:See our website for the following add on accessories
SEAMINI
JBLREM20 –DIN-AMP adapter required
SEAMINI or SEAMINI2 –RCA to 3.5mm head phone jack
JBLREM21 –DIN-AMP adapter required
JBLREM25 –DIN-AMP adapter required
JBLREM30 –DIN-AMP adapter required
Sirius SCC1 tuner- we don’t sell
JBLREM35- we no longer sell
JBLREM40- DIN-AMP adapter required
JBLREM45
JBLMC19
JBLMC18/18.3-we no longer sell
MIL-BTREC
Any 4 channel amp OR 2 channel amp and subwoofer
Remote adapter and extensions
REX20-13 remote extension –fits REM35 and REM45, MC-19 and REXW-13.2
REXW-13.2–three way splitter for REM35/45, MC-19 and REX20-13
3.0. List of common issues
3.1 No Power
•Check each button on the control pad for sticking. Under normal conditions, a faint click is heard upon pressing each
button. If any button does not click, initiate a warranty claim.
•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 may
not 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 11.5V to
operate normally.
•Check all connections for corrosion, looseness, or other condition that can produce a bad ground. Corrosion or
terminal looseness is the leading cause for most grounding issues and can cause excessive heat resulting in melting
wires or terminals.
•Unplug any remotes or extension from the back of the stereo to determine if the root cause is with another
component.
3.2 Intermittent Power
3.2.1 Powers on and off constantly
Check voltage under load. At least 11.5V 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. Wiggle connections while the radio is operating
to produce the symptom and narrow down the loose connection. If radio cuts in and out while wiggling the wires on
the radio side of the wire harness, initiate warranty claim.

3.3 Buttons/controls not responding or behaving erratically
3.3.1 Symptoms
•Stations scanning continuously
•Run away volume
•Controls frozen
•Frozen screen
•Broken characters on screen
3.3.2 Troubleshooting without remotes
•Check each button on the control pad for sticking. Under normal conditions, a faint click is heard upon pressing
each button. This includes the volume and tuning knobs which should also click when presses. If any button does
not click, initiate a warranty claim if you are under warranty.
•Reset the radio (reset procedure in 7). Try radio again.
•Cover the infrared eye (this eye is to the left of the TUN/TRK nob [your radio may or may not have this]). If the
radio and remotes work, initiate a warranty claim for the radio because the tuning eye is causing the problems.
•Initiate a warranty claim if you are under warranty and the above does not work.
3.3.3 Troubleshooting with remotes
Follow the above in 3.3.2.
•Detach any additional equipment connected to the radio such as remotes, remote adaptors, and extensions.
•If the stereo returns to normal operation, plug one attachment in at a time until the discovering the defective
part.
•Check all remote connections for water intrusion or corrosion. This includes any extensions connected to the
radio or remote. If any connections are corroded, replace the corresponding part. The best corrective measure to
prevent this from happing again is to seal this connection with an adhesive shrink tube and heat gun. If these
materials are not readily available, make sure all connections are higher than the mounting location of the
remote and radio so any water entering these areas does not follow along the cable and into the connection.
Also make sure these connections are in dry areas.
Look for a cupped remote connection. Radios with SN# AL07/1875/1107, AL11/8846/1111, and AL01/4468/0212
will have this connector. This connector might be causing this problem. Contact us if you are within warranty.
Initiate warranty claim if you are under warranty for defective parts.
IF THERE IS ANY CONFUSION ABOUT THIS PROCESS, PLEASE SEE OUR TROUBLESHOOTING VIDEO FOR ERRATIC CONTROLS
CUPPED
CONNECTOR
Cupped connector Good connector

3.4 Poor or no Reception
3.4.1 For an amplified antenna
Ensure the antenna is connected to power and ground according to manufacturer’s instructions
The antenna wire should never be coiled or wound up.
Check proximity of radio, speakers and antenna to gages, GPS equipment, depth finders, LED lighting or any
other source of Radio Frequency Interference (RFI) and Electronic Magnetic Interference (EMI).
3.4.2 For all other antennas
Inspect the antenna for torn wires.
The antenna wire should never be coiled or wound up.
Check proximity of radio, speakers and antenna to gages, GPS equipment, depth finders, LED lighting or any
other source of Radio Frequency Interference (RFI) and Electronic Magnetic Interference (EMI).
3.4.3 LED lighting causes low FM/AM audio or poor reception
•Never bundle the power source wires of the LED lighting to the power wires of the radio.
•If needed, the LED power wires and radio power wires should intersect at a 90 degree angle.
•The radio’s antenna must be as far away from the LED lights and power source as possible.
•The radio’s speakers also must be as far away from the LED lights as possible
•If all fails, upgrade the LED lights to a brand that is guaranteed not to emit RF or EMI.
3.5 No audio, speaker audio is unevenly distributed or some speakers not working
•Check Balance settings. To access and adjust these settings, press SEL button. Quickly press the SEL button again and
again until the desired setting is displayed. Use the volume buttons to adjust. Center the adjustment between
left/right.
•If an AUX device is plugged in and being used (like an iPod or MP3 player), make sure the volume is turned up
•Check speaker connections. Ensure each speaker wire is routed to the appropriate speaker terminal for which it is
intended.
•Inspect all speaker wires for exposed wire and tape up as necessary. Make sure they cannot ground to one another or
make contact with any other potential power source or ground. NEVER combine speaker wires.
•If some speakers are working but others are not and the above methods do not help, swap the known working
speakers with the ones that are not working. This will help determine any defective speakers.
•If no audio and the above methods yield nothing, initiate a warranty claim if you are under warranty.
3.6 Low Audio
•Check speaker specifications –recommended impedance is 4ohm
•Check sound enhancements - To access and adjust these settings, press SEL button. Quickly press the SEL button again
and again until the desired setting is displayed. Use the volume buttons to adjust.
•Use the LOUD feature by pressing the LOUD button
•LED lighting can cause low FM/AM audio
•If an AUX device is plugged in and being used (like an iPod or MP3 player), make sure the volume is turned up
3.7 Fluctuating audio or FM signal - Audio level constantly raises and lowers when the engine is started or revved. This
issue is more frequently caused by power fluctuations than radio failure.
•Check to ensure ground is good and no corrosion exists at connection points.
•Check all power wires for corrosion at connection points.
•Check for corrosion at battery terminals, bus terminals, and fuse panel.
•If in a boat or another motor vehicle, ensure the recommended plugs are being used the engine. Resistor plugs can
often block unwanted RF signal that can interfere with radio reception.
•LED lighting can cause fluctuating FM/AM audio

3.8 Moisture in Display
3.8.1 Water seen inside display after washing the mounting area
•Radio is not designed to withstand pressurized streams of water. When rinsing the radio or around the radio, a
very low pressure spray is recommended.
•Monitor the radio for strange or erratic behavior. If the issue persists, internal damage has occurred- seek to
repair or replace.
3.8.2 Slight Fog after operation
•Normal in cold weather but monitor
3.8.3 Heavy Condensation
•The condensation may evaporate without harm to the radio.
•Monitor for strange or erratic behavior. If the issue persists, internal damage has occurred. Seek to repair or
replace.
3.9 CD player won’t work
If new radio, check to make sure the transit screws are removed. These are the 2 screws on the top of the radio.
Make sure there is only 1 CD in the mechanism at a time.
The MR18.3 only supports Analog CDs (i.e., store bought CDs)
Reset the radio. See 7for more information.
If nothing else works, initiate warranty claim if you are under warranty.
3.10 CD door won’t close/open
Initiate a warranty claim if you are under warranty.
4.0 External Amplifier Issues
4.1 Strong Hiss
•Reduce the input gain on the amplifier until the hiss is reduced to an acceptable level while still maintaining
performance. Note, if both amplifier and stereo output can produce distortion, the input gain is much higher than it
needs to be. In most situations, reduce gain levels will not produce detectable performance conditions.
4.2 Amplifier volume fluctuates or amplifier turns off and on
•Check the grounds to both amplifier as well as radio. Corrosion on any of the contacts will reduce the ground
•Check the system voltage while operating the radio and amplifier. If the voltage fluctuates and drops below 11.5 volts,
load test the battery, check the charging system, and check all power and ground wires/contacts for looseness or
corrosion.
•Ground the amplifier’s chassis to the stereo’s chassis.
4.3 Audio is extremely low
•Check the amplifier’s gain setting and increase if necessary.

5.0 Sirius Problems
5.1 Common Installation issues
5.1.1 Does not receive channels or stay in Sirius mode
•Ensure a Sirius tuner and antenna is connected to the stereo. Check the wiring diagram in section 1 of this guide for
location of the Sirius tuner connection.
•Ensure the correct Sirius tuner is installed. See section 2 of this guide.
5.1.2 How to display the Sirius SID number on the stereo
•Method 1 - Using the tuning knob, tune to channel 000.
•Method 2 - Press and hold the MOD button then press the LOUD/0 button three times.
5.1.3 Cannot display the Sirius SID number
•perform the same check points as in above section 5.2.1
5.1.4 LCD displays “Check Antenna”
•Antenna is disconnected from the Sirius tuner.
•The antenna has lost line of site from the satellite.
5.2 New issues on previously working systems
5.2.1 Does not receive channels or stay in Sirius mode
•Check connection between stereo and Sirius tuner for looseness or possibly disconnection.
•Check the same connection for corrosion or rust.
•Replace Sirius tuner.
5.2.2 Displays “Check Antenna”
Antenna to satellite line of site is disrupted.
Check antenna connection to tuner for disconnection or looseness.
Check the same connection for corrosion or rust.
Note: If Sirius is not connected with the correct tuner and antenna, then the MR18.3 will show Sirius, and then skip over Sirius
after a delay of 5-10 seconds.
6.0 Reset Procedure
Press the reset button behind the radio faceplate while the stereo is on
Hold down MOD and BND button simultaneously until the stereo powers down (this will reset all presets).
Disconnect the 12 pin connector plug for about 15 seconds
7.0 Lubrication of Tuning Knob –necessary if either or both knobs become slow or unable to return to center position.
7.1 Material and tools
A good quality non-stick cooking spray –this type of lubricant is highly lubricating, easy to use, and will not corrode or
swell the rubber membrane which surrounds the shaft of each knob. Petroleum cut lubricants such as silicon sprays or
anti-rust lubricants are not recommended as they will permanently damage the rubber membrane.
A toothpick or other very thin but blunt round object.
A pair of pliers.

7.2 Method
Gently remove the rubber boot from the desired knob using your fingertips.
Grab the exposed plastic knob with pliers and gently pull the knob from the shaft.
Using a toothpick, gently work the cooking spray between the shaft and rubber membrane lubrication the entire
perimeter of the shaft.
DO NOT INSERT TOOTHPICK MORE THAN 1/16 INCH AS THIS CAN PUNCTURE THE RUBBER SEAL RESULTING IN
PERMANENT DAMAGE.
Repeat if necessary.
Reinstall the plastic knob taking care to align the keyway of the knob the flat part of the shaft.
Reinstall the rubber boot.

7.4 Testing
•Twist the knob in one direction and let go. The knob should quickly bounce back to center.
•Repeat the step above but now in the opposite directly.
•Check other controls on the stereo for proper operation.

8.0 Location of Production and Serial Numbers –These numbers are found on the silver label location on the bottom of
the radio’s chassis. See below example.