Mon-Thursday 8am - 3pm PST

Installation of the HRR688 Ignition Module:

  • Congratulations, you now own the finest most accurate and dependable Ignition Control Module ever produced, Made in America and backed by a 5 Year Limited Warranty
  • Every HRR688 Ignition Box is test run on a distributor machine before it leaves assembly. You must have a good ground from the engine to the firewall and the box must be grounded to the firewall. Check all grounds.

You must jumper or hard wire to eliminate the Ballast Resistor, although the engine will probably start with the ballast, this will deliver a low voltage signal to the ECU/Coil and prolonged running will cause failure, this is easy for us to determine and is not warranty claimable.  Voltage to the ECU should be at or just below battery voltage with the key in the run position, usually 11.5 to 13 volts.

We also recommend a small amount of dielectric grease on each pin to help prevent any corrosion buildup in the plug. Do Not Over Tighten the plug lockdown screw! USE ONLY screw provided. Only use DOT Approved Cross-Link wire for your Ballast Jumper or any wiring on your car.

REV Limiter at 0 is 5200 RPM, each click is 200 RPM to 9 which is 7000 RPM


Mopar Mechanical Limiter Disc to limit your total advance and allow for more initial timing. 0-10-12-14-16 or 18*.


Use Jumper to Bypass Ballast or solder the wires together and eliminate Ballast. Included in every kit.


Using MSD or Daytona Billet distributor with Bushing style advance limiter? Order our 10 and 14* limiter bushing kit to get more initial without exceeding mechanical advance limits.

  • No matter how good the Control Module you have is. You still must have the distributor curved for optimum performance. FBO Mopar Limiter Disc (left), Ballast Jumper (center), and MSD Bushings (right). Contact us for more information.
  • We recommend a 032-036 Plug gap on standard plugs. Excessive plug gaps cause erratic combustion and overload components with no enhancement to ignition performance. High compression and race engines using a Race Plug may require even tighter plug gaps, follow plug manufactures recommendations.
  • Do NOT take this ECU to any Parts House or shop for testing. It is a computer based unit and can NOT be tested with a conventional ECU tester of any type, no matter what they tell you. There are NO transistors in this unit to test. No modifications to the processor programming can be accomplished from any of the exposed terminals, if there were any modifications to the program that may improve its performance we would have already done it. Incorrect testing may cause catastrophic failure and is not covered by the warranty.

If at any time this box should have any issues contact us so we can walk you through the testing procedure.