I am having similar problems with my Smart car, no brake lights unless ignition on - Roadmaster suggest putting it up on a ramp, drilling holes and installing a separate switch - way too expensive an option.
The issue with the way I have wired it which is MH -> SMART lights with a tap out to the ICX, is that I can initialize the self test mode by keeping the Smart ignition on while it tests itself and then returning the key to off for the tow.
However the remote unit indicates all is well until I touch the MH brakes - then I get a warning/error saying that the brake lights are on but the EB isn't braking.
So I picked up a microswitch which I am attaching to the body of the EB with a cord that goes to the part that attaches to the brake pedal - when the brake pedal is pushed by the EB it pulls the cord that closes the contacts on the switch which is fuse wired to 12V - fools the EB into believing that it has fully operational lights.
I have no idea why they designed the software to disable the EB just because the brake lights are not working - in 99% of cases, the toad brake lights are operated by the MH anyway.
