Thats the diesel specific manual and that is a good price. It will not cover the wiring diagrams.
Chock full of very detailed diesel specific service, diagnostic, rebuild, specs, tools needed etc. Little over 1 inch thick.
For accessories, suspension, brake jobs, electrical diagrams, axle and various transmission (not Getrag) info as well as body, HVAC and more you need the regular FSM. As thick or thicker than the supplement.
Here's a link to the 91.5' wiring schematics right out of the regular FSM, now go buy the Diesel Supplement, when you confirm the good stuff you can pull the trigger on the regular manual...
http://dens-site.net/Dodge_CTD/1991.5-Wiring_Diagrams/
