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Siren FAQs

If you are unable to find the answer to your questions, please fill out our online contact form, email us, or call our Customer Service Department at 888.577.6877.


Sales & Service:




Sales & Service:

Q: How can my Department arrange to see a product demonstration?

A: Requests for product demonstrations may be made by contacting your area’s Sales Representative, a Dealer or by contacting Carson Sirens directly. To find a representative or dealer in your area, please refer to the Siren Dealers page.

Q: Can I buy directly from the factory?

A: No, Carson sells our emergency vehicle products through a network of Sales Representatives, Dealers and OEMs. To find the Sales Representatives and Dealers in your area or to find the OEMs currently offering Carson Sirens, please refer to the Siren Dealers page.

Q: Will Carson “drop-ship” products?

A: We strongly discourage this practice. However, we understand that some situations are unique and require us to go that extra mile to support our customers. In those types of situations, we will “drop-ship” products for an additional fee.

Q: How can I become a Carson Dealer?

A: If you are a Dealer or OEM and are interested in carrying the Carson Sirens line, please contact your area’s Sales Representative or Carson Sirens directly. To become a Carson Sirens Dealers, both the Sales Representative and Carson must approve a potential dealer. Dealers may apply for credit.

Q: Where can I get installation instructions?

A: Each of our emergency vehicle product manuals includes detailed installation instructions.

Q: Are replacement parts available for Carson Sirens or SVP and Galls sirens originally manufactured by Carson?

A: Yes, replacement part numbers for each product manufactured by Carson are listed towards the end of that model’s product manual. Contact our Customer Service Center to place your order or for further information.

Q: What do I need to do for a warranty or non-warranty repair?

A: If a product must be returned for any reason, please contact our Customer Service Department to obtain a Returned Merchandise Authorization number (RMA#) before you ship the product to Carson. Please write the RMA# clearly on the package near the mailing label. Send the unit back to our Service Center for repair at 5451 North Rural Street, Indianapolis, Indiana 46220. Include your name, address, phone number and a description of the problem experienced with the unit. Warranty repairs will be completed and returned.

For billable or non-warranty (outside of warranty period) repairs, the unit’s problem will be assessed and you will be contacted with an estimate for repairs. Effective July 2, 2010, all non-warranty repairs are subject to a minimum diagnostic/repair charge of $60 for labor, plus $15 shipping and handling for deliveries in the USA. After diagnosis, you will be informed of the total cost for parts and labor. If the repair is declined, the $60 diagnostic charge, plus shipping and handling, will apply. Any unit that is 10 or more years old is subject to a $120 minimum charge. Whether a repair is covered by warranty or not can only be determined after the unit is examined by a Carson technician.

Any item which is found to have no fault will be charged $60 for diagnostics, plus shipping and handling. This includes units that are still within the warranty period. For this reason, please ensure that the problem is not due to bad wiring or other external causes. You may find it helpful to refer to the troubleshooting guide in the siren installation manual. You may also contact Carson’s technical support team for assistance in troubleshooting. We will do all we can to help you identify the source of the problem and provide the information necessary for you to make the best decision in regards to the repair options for your unit.


Q: What is an Auxiliary Input?

A: The Auxiliary Input is a wiring input that may be connected to the vehicles horn ring or other switching device during installation. It provides the driver with “hands-free” operation. When connected, the vehicle’s horn works like the Siren button if the siren has only one momentary override button or your choice of Air Horn or Manual/Phaser if the siren has two momentary override buttons. When the Auxiliary Input is connected, you may also choose to replace the Auxiliary Input function by activating the Horn Ring Cycler (HRC) or Horn Ring Cycler 2 (HRC2) function.

Q: What are the Horn Ring Cycler (HRC) and Horn Ring Cycler 2 (HRC2)?

A: With the Auxiliary Input connected and the Horn Ring Cycler (HRC) or Horn Ring Cycler 2 (HRC2) option selected, then the driver may scroll through wail, yelp and phaser tones by tapping the vehicles horn for “hands-free” control when the siren selector is in the Standby position. Pressing and holding the vehicles horn produces an Air Horn override tone without changing the basic tone selection. Pressing twice in succession will turn it off.

Q: What is Siren Cutout?

A: Also referred to as the Park Kill function, the Siren Cutout input is connected to the driver’s side door switch and turns off any siren tone when the door is opened. The siren tone remains off even when the door is closed and will not resume normal function until a siren switch or input is activated.

Q: What is Instant On?

A: Instant On is a feature that allows the unit to be powered up without using an on/off switch. Selecting any function in normal use operation activates the unit.

Q: What does the Output Indicator do?

A: The Output Indicator is a sensor that lights up when it senses the siren sending out a signal to the speaker(s). This provides a quick and easy diagnostic feature to help pinpoint problems between a siren, speaker(s) and speaker wiring.

Q: What is DIP switch programmability and Face programmability with User Lock-out?

A: DIP switch programmability is an improved method for selecting how a unit will function over traditional jumpers. A DIP switch allows the installer to easily turn on or off select functions to semi-customize the unit for the desired environment. Face programmability with User Lock-out allows the installer to completely customize the unit for their specific needs through a push of the buttons and then they can lockout users from re-programming in the field.

Q: What is Dual Tone?

A: Dual Tone is when a siren produces two tones at the same time. It sounds like two sirens in one. Carson developed and perfected the dual tone technology over 15 years ago with the development of the independent 2-channel amplifier. The SA-441 is the original dual tone siren.

Q: How does the independent 2-channel amplifier work?

A: The independent 2-channel amplifier is basically two 100-watt amplifiers encased in one unit. When in single tone mode, the two amplifiers work in unison, but they work separately when switched to the dual tone mode.

Q: How do the short circuit, high voltage and reverse polarity protection systems work?

A: These systems are all incorporated into the circuit board to protect the amplifier from damage. The short circuit protection system protects the amplifier from a shorted or blown speaker. It senses when a short occurs in a speaker and blows the fuse to keep the amplifier components from overloading.

The high voltage protection system protects the speaker from the amplifier when spikes in input voltage occur. The high voltage sensors detect when the input level rises above 16 volts and kills the sirens output. The siren automatically resets when voltage levels drop back down to normal levels.

The reverse polarity protection system protects the amplifier by blowing the fuse if the power input connections are improperly connected. For example, if the positive wire is attached to the negative connector, the fuse will blow.

Q: What does a single lead connection mean on the remote sirens?

A: This patented design allows for all of the exchange of information between the control head and the amplifier to travel through a single #22 gauge wire. That means that during installation, the installer must only string one wire from the control head, through the vehicle and back to the amplifier rather than stringing as many as 10 wires back through the vehicle to the amplifier.

Q: What does the Master Switch do on the switch box?

A: The Master Switch allows the SB-008 Phantom switch box to function like it had a slide switch. When programming the switch box, you can group different switches together to be controlled by a Master Switch. When the Master Switch is activated, all of the switches in the group are activated like when a slide switch is in the 3rd position. The driver may then de-activate individual switches within the group to back-down the number of lights activated like when moving back to position 1 or 2 on a slide switch.

Q: What common additional options are available?

A: Carson has detachable microphones and 28-volt versions for large vehicle installations available for all siren models. In addition on our remote sirens, we offer amplifier or control head only packages for component replacement and FX extended detachable microphones for remote microphone mounting. Our SC-550 has a 15′ extension cable for the hand-held control head.


Problem: Unit is not coming on.

A: First of all, make sure the power switch or ENABLE input is connected, that a connector is not loose, and then check for blown fuses including any external fuses or circuit breakers. Next, check for loose wiring connections and make sure that the negative leads are well grounded. Finally, check to see if the speaker(s) are bad.

Problem: The microphone works, but the siren tone is not working.

A: Check to make sure that the microphone push-to-talk button is not stuck in the on position. Next, if your unit is equipped with a Siren Cutout feature, check to see if the polarity option for the cutout feature is correctly selected and then see if the siren works when the feature is disconnected. Finally, check to see if the input voltage is above 16 volts (or 32 volts for 28 volt sirens). If it is, then the input voltage will need to be reduced in order for the high voltage protection system to reset.

Problem: The PA function does not work.

A: Try turning the PA volume control knob to make sure the volume is turned up. Then check to see that the selector is not in the Radio position (PA is not available when Radio is selected).

Problem: Siren tones sound distorted.

A: Check for loose speaker wiring connections. If the Auxiliary Input is connected, check to insure that the feature is wired properly. Lastly, check the vehicle for low voltage. The input voltage must be greater than 9 volts.

Problem: Siren tones are working intermittently.

A: First, check to see if anything might be contacting and activating the PA microphone, then check to see if the connector is securely connected to the unit. Next, check for a loose power supply lead and make sure that any circuit breakers are rated at least 50 Amps. Finally, check to see if the vehicles voltage regulator is malfunctioning and causing the high voltage protection system to trip.

Problem: Air Horn or Manual function staying on.

A: Most likely you have a sticking (Air Horn, Manual/Phaser or Siren) momentary switch. Check to see if they return fully when released. If the Auxiliary Input is connected, make sure it is wired properly and the correct polarity setting is selected.

Problem: Radio function is not working.

A: If you can hear the Radio in the vehicle, adjust the Radio Volume control located either on the face of the unit or on the amplifier clock-wise to increase the volume level. Also, make sure that the Radio function is connected properly to the unit.

Problem: The wrong siren tone comes on.

A: Check the option switch settings on the DIP switch to make sure that the tone selection options and Auxiliary Input options are set correctly for your application. Check to see that switches are wired properly on the SA-361 whether using the Carson switch panel or connecting to existing switches.

Problem: Phaser or Air Horn tone is not working.

A: Check to make sure they have not been disabled on the DIP switch.

Problem: The dual switch is not working on the SA-441.

A: The siren will continue to function even when one of the amplifiers is not working. Check the fuses on the amplifier. Then check to see if one of the speakers has been damaged and replace it.

Problem: The SA-441 amplifier is constantly blowing fuses.

A: This will happen when the amplifier is not wired properly or when the connector is not installed correctly. Check to make sure that Speaker A and Speaker B are not wired together and that the connector is inserted correctly.

Problem: Manual stops immediately.

A: Some units have an option setting for Short Manual. Check the DIP switch settings to change this feature.

Problem: Automatic siren is not working when I throw the lever or slide switch.

A: Check to make sure the selector is not in the Radio setting. Also check to see if the automatic Siren Disable option is selected on the DIP switch. On the SC-407 siren only, check if the leads are cut between the lever switch board and the siren board.

Problem: Automatic siren works in all positions.

A: On the SC-407 only this may occur when power is not reaching the light control board. Check to see if the indicator lights for the lever switch are functional and do the lights work with the lever switch on.

Problem: Lever or slide switch not working or not working in some positions.

A: When the lever or slide switch is not working at all, check the fuses, make sure power is reaching the light control board and check that the unit is properly grounded. Lastly, look at the internal relay contacts to see if they have gone bad from overloading the output current limit. If the lever or slide switch is not working in some positions, then there is most likely a loose output connection on the lever switch lead.

Problem: Light output stays on.

A: This typically happens when the internal relay contacts fuse together from overheating as a result of the output current exceeding the limit.

Problem: Auxiliary light control switches not working.

A: First check to see if corresponding fuse is blown. If the auxiliary light control switch is a rocker switch, check to see if the output lead is loose.

Q: How can I tell if it is a siren or speaker problem?

A: On sirens like the SA-500 and the SA-360, it is quite easy because of the output indicator. Sirens with an output indicator have a sensor that senses when the siren sends out a signal to the speaker(s). If the siren has been activated, but there isn’t a tone coming from the speaker, then the problem is with the speaker or speaker wiring.

If your siren does not have an output indicator, then the best method is to listen closely to the siren amplifier box. If you can hear a faint siren tone, then the problem is with the speaker or speaker wire. Another method is to switch speakers and see if problem continues to persist. However, this method will falsely indicate a siren problem if there is damaged speaker wiring.

NOTE: All Carson sirens are intended for use by authorized personnel only. It is the user’s responsibility to ensure they understand and operate this emergency warning device in compliance with all applicable city, state and federal laws and regulations.