User Guide
Page 10 of 12  Installation and Operating Instructions  SC-411RD-10 
7/30/12  CP5094C 
SERVICE 
This  unit  is  designed  to  provide  years of  reliable  service  under  even  the  worst  conditions.    Many  times  there 
may  appear  to  be  a  problem  with  the  unit  when  the  true  problem  is  in  the  speaker(s),  controlled  devices,  or 
improper installation. The following chart shows typical symptoms and possible causes. 
A blown siren fuse  doesn't necessarily mean that the unit is bad.  If a speaker or speaker lead is shorted the 
internal fuse will blow before the unit is damaged.  Disconnect the speaker leads and replace the fuse.  If the 
OUT/DIM light comes on with power on and Yelp selected it is OK.  Check the speaker(s) or leads for possible 
shorting. 
PROBLEMS 
PARTS 
The following parts are available from Carson Manufacturing Company, Inc.:
Symptom  Possible Cause  Check 
No power or siren 
output 
No power to POWER input 
Bad speaker 
Connector(s) loose 
Amplifier fuse blown 
Loose connection at power source 
Does backlighting come on? 
Do you hear a "pop" when turned on? 
With siren on and Yelp selected, listen for tone in amplifier. 
Is an external fuse or circuit breaker used? 
Are the negative leads connected to a good ground? 
No siren tone - PA 
works 
High Voltage Protection 
Microphone button stuck 
Cutout activated 
Cutout Polarity set wrong 
Input voltage must be less than highest rated voltage. 
Does microphone button release properly? 
Does the siren work when CUTOUT input is disconnected? 
Is the Cutout Input option properly configured? 
No PA  PA volume not set properly  Have you tried adjusting the PA volume control? 
Distorted siren 
sound 
Speaker assembly loose 
Intermittent SIRCTRL Input connection 
Low vehicle voltage 
Is the speaker bell or tip loose? 
Is the SIRCTRL Input used and wired properly? 
Input voltage must be greater than lowest rated voltage. 
Intermittent siren 
tone 
High Voltage Protection 
Connector loose 
Bad power connection 
Microphone button activation 
Circuit breaker in supply connection 
Is the vehicle voltage regulator working properly? 
Is the connector tight on the back of the unit? 
Is there a loose connection on a power lead? 
Is something lying on the microphone? 
Are circuit breakers used with at least a 50A rating? 
Horn function stuck 
on or 
Manual stuck on 
Horn or Manual switch stuck 
SIRCTRL Input improperly connected 
SIRCTRL Input Polarity Option set wrong 
Does the horn or manual switch return when released? 
Is the SIRCTRL Input used and wired properly? 
Is the Siren Control option properly configured? 
No Radio  Unit not connected to radio 
Radio volume too low 
Is the radio connected properly to the unit? 
Can you here the radio in the vehicle? 
Have you tried adjusting the radio volume control (amplifier)? 
Wrong siren tone  Two-Tone option installed 
Aux Input set to wrong function 
Is the Two-Tone option selected? 
Is the Sweep/Intersection option selected? 
Phaser or Horn not 
working 
Tone disabled  Is Phaser/Two-Tone Enable option selected? 
Is the Horn Enable option selected? 
Automatic Siren not 
working 
Automatic Siren disabled  Is the Automatic Siren Enable option selected properly? 
Lever switch not 
working at all 
No power to lever switch 
No ground at siren connector 
Do the lever switch indicators light? 
Does the siren work? 
Lever switch not 
working in some 
positions 
Loose lever switch output connection  Does the lever switch indicator work in those positions? 
Is the corresponding fuse blown? 
Aux control switch 
not working 
No power to aux switches 
Loose aux switch output connection 
Do the aux switch indicators light? 
Is the corresponding fuse blown? 
Part  Description 
ED1943  Kit, Control Head Mounting (2-brackets, screws and lockwashers) 
ED1944  Kit, Lever Switch Replacement (Includes mounting screws & CP4960 knob) 
CP4688-12  Connector, 12-Pin Removable Terminal Block 
CP5086-03  Connector, 3-Pin Removable Terminal Block 
CP5090-25-BK  Cable, CAT5e 25ft Black 
CP4990-150  Fuse, ATM 15 Amp Automotive Mini 
CP4990-250  Fuse, ATM 25 Amp Automotive Mini 
CP4960  Knob, Black Lever Switch 
CP4852  Knob, Black Rotary Switch 
CP4895  Label, Aux Output Legends 
CP4750  Microphone, Noise Canceling w/Connector 
CP3633  Microphone Bracket with mounting screws 
SR-15-1  Microphone Strain Relief 
CP4119  Transistor, Output (2 required) (Industry Standard TIP36C, must have metal tab) 
CP5094  Manual, SC-411RD-10 Installation and Operating 
CP4688-10  Connector, 10-Pin Removable Terminal Block 










