Update on 93 ZJ no brake lights:
GREMLINS! No other explanation. Cops stopped me and said my brake lights were out. I had replaced the LOM module a couple weeks ago and everything worked fine. Now, I have tail and blink but still no brake. When the incoming plug is disconnected from the LOM, all circuits check out fine. As soon as it is plugged in, the signal from the brake switch (white w/brown stripe wire) disappears. When I bypass the LOM and plug it up directly, the results are the same. So I jumpered a spare bulb directly to the incoming wire, it would not light the bulb, but it will light up the tester bulb.
I am absolutely stumped by this one. Meanwhile, the truck has an impound order on it if back on the road w/o brake lights. Wire the brakes to a separate relay that could be activated by the incoming brake signal?