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Converting an Old Whelen PCDS-9 Edge 9000 Lightbar Into a PCCS

Jason Ponic works in the exciting world of Hollywood film and television by day and writes by night.

Lightbars are common features on law enforcement agency vehicles.

Lightbars are common features on law enforcement agency vehicles.

The Whelen® Edge 9000 Series

It's been one of the most popular lightbars of all time. The Whelen® Edge was launched in the early 1990s as one of the first non-rotator lightbars available to law enforcement. Using patented state-of-the-art strobe technology, these lightbars offered a lower profile, greater customization, and more durable solid-state construction than Federal Signal® or Code 3® rotator bars. As the popularity of the Edge grew, so did the number of variations offered by Whelen. Some configurations became industry-specific. The Whelen Edge Towmaster, for example, was an Edge 9M bundle kit specifically offered to tow trucks. As the years progressed, the circuit technology also improved with some of the first "smart" computerized lightbars entering the market. Enter the Whelen Edge 9000 PCDS-9.

The PCDS-9

Their first smart lightbar, the PCDS-9, (Power Center Diagnostics System) used serial communication between the control and the lightbar to send flash patterns or steady burn codes. This lightbar had the revolutionary ability to tell if a lightbulb or fuse was burnt out and would send the error code to the control box in the form of a flashing light. The serial communication also eliminated thick and bulky power/control cords to the lightbar making installation and maintenance easier. In their place was a simple power cable and a thin serial communication cable.

What made the PCDS-9 revolutionary also gave it a short service life. The control boxes were flash programmed into memory by Whelen for just one specific lightbar configuration. Whereas the PCCS used direct wire connections that could easily be reconfigured by the user if lightbars and control boxes were swapped, the PCDS memory could only be reprogrammed by Whelen. If you were trying to plug in an Edge with a Traffic Advisor to a control box that was not programmed to support a Traffic Advisor, the resulting error codes would not allow the bar to function properly. As a result, unless you were lucky to purchase a PCDS-9 with its original control box, the odds of finding a comparable box were very slim. When Whelen finally stopped supporting the PCDS, the ability to have them reprogram control boxes ended. At that point, control boxes were all but worthless and the PCDS system lightbars were simply sold for parts.

Is Conversion Possible?

So say you are in the same predicament I found myself in where you have a PCDS-9 bar you want to resurrect but have no compatible control box. What do you do? Simple. Convert it into a PCCS-9 system!

Since Edge 9M bulbs or housings themselves haven't changed over the decades, they are completely interchangeable regardless of the circuit boards or control box. If you have a lightbar where all bulbs still work, it's easy to replace the circuit boards with no soldering or rebuilding of any wiring harnesses.

What Do You Need to Convert?

The PCDS-9 lightbar I intended to convert came out of the Bernalillo County Sheriff's Office, specifically from a blue/white generation early 2000s Crown Victoria. It is a four-corner strobe Edge with four halogen front flashers, two doubled as takedowns. The rear edge contained an eight halogen lamp traffic advisor. These were used for ten years in tandem with Federal Signal Vista lightbars before being replaced with Code 3 LEDx lightbars.

The parts in this PCDS-9 system that needed to be replaced:

  • Serial Communication/Driver Board
  • Serial Diagnostic Sensor Board
  • Serial Traffic Advisor Control Board
  • Serial Communications Cable
  • Serial Wiring Harness.

These were the parts needed as conversion parts.

  • 94 Series Matrix Board
  • Halogen Flasher Board
  • Internal TA cable harness and External TACTRL 1 TA Control Head x 1
  • PCCS Control Multi-Cable x 1
  • Strobe Wire Harness x 2

These were the parts that could be carried over between the two systems.

  • Power Cable x 1
  • Takedown wire harness x 2
  • Alley light wire harness x 2
  • Strobe Power Supply x 1
Stripped out Edge lightbar.

Stripped out Edge lightbar.


After removing all the PCDS-9 boards and wires, you're effectively left with an empty frame. Even the carry-over parts should be removed to make it easier for installation. You will find everything is plug and play with each cable and socket. The strobe system uses an entirely different socket than the halogens so there is no risk of cross plugging.

The 94 matrix board, while shorter, mounts in the same position as the original serial receiver board. You will notice two positive and two negative prongs, a set for the strobes and a set for the halogen. Plugging the original power cable into one of these sets and running cross wires to the second set will omit the need for a second power cable.

The halogen flasher board mounts where the serial traffic advisor board was. The inputs plug into the fused slots on the matrix board.

The Traffic Advisor is independently driven. The wire harness is a simple eight slot chain wire that connects directly to the external control head. All eight lamps are controlled and powered by this harness and do not rely on the main matrix board at all. The traffic advisor can fire even when the main board is unpowered.

The 94 matrix board installed.

The 94 matrix board installed.


You should never power your lightbar in a disassembled state. During installation, you should always use a meter to determine what ports and prongs are which. Accidentally grounding the wrong wire can fry the matrix board permanently.

Completed Conversion

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.