I needed to dust the manual off myself... My ABS light has been non-functional since acquiring the van in 2005 and have locked the brakes several times (Snow/rain) and can say with confidence it isn't working... No brown-trouser marks yet...
I can see the rear ABS module, but as best I can tell, the ABS modules on the front two wheels are missing, which raises quite a few questions. I'll probably dial up Quigley and ask what model & year the axle is off of... I'd really hope that Quigley didn't bolt up a non-ABS front axle and chop the ABS lines off, but the general consensus seems that front ABS on F-series was optional at the time, so who knows.
Best of luck! If you need other photos I'm happy to post what's in the manual.
1997 Quigley E-250