[30 Closed Cab PU]

There is another option if your issue is due to radiated noise, and is not conducted noise through the wiring into the flasher unit.




You can try to shield the sensitive components. We do not know where your electronics is, but fab a shield using a few layers of aluminum foil that wraps entirely around the electronics. 1st try shield un-grounded, then try grounding the foil. This is something easy/quick to try to troubleshoot.



Just for kicks you additionally at the same time could try doing the same with the distributor body to attempt to reduce amount of radiated noise due to the rotor arcing. You would have to insulate the shield so the high tension and plug wires/etc do not short out the plugs.


I've often wondered the effect of resistive wires or resistor spark plug wire caps have on the quality of the spark plug spark. Old motor cycles use 5k ohm caps, Without the 5k ohm caps the plug spark seems more intense. So I wonder if these types of wires/caps affect the Model A performance, perhaps the plugs do not run as clean/etc?


If you really run into issues, perhaps try talking to an car stereo installer with experience on classic cars.