Just out of curiousoty, was it hard to convert to propane?I have both Haynes and Chilton books for every vehicle I have owned. They all had a full pin layout diagram relating to the EEC or ECU systems.
That is the wiring diagrams show the EEC or ECU as a block with numbered lines and color abbreviations coming out of it that correspond to the pin number and the wire color code. From that I have been able to trouble shoot electrical problems with little difficulty.
However it should be noted I have all Ford vehicles and it may be likely that what I have for electrical reference may not be in all books relating to all makes and models.
Most auto dealerships will let you have a full copy of wiring diagrams for your vehicle for free if you talk to the right person. I have never had any trouble getting additional service files from any of the local dealership repair shops when I had a wiring question that I felt the Chilton or Haynes books were possibly missing something.
I did a full propane conversion of a 1999 Ford F250 Super duty last year and needed to find out exactly how I shut off the fuel injectors without the computer knowing about it and where to tie into the O2 sensor lines in order to send false O2 sensor signals back to the computer so as to fool it into thinking it was still running on gasoline.
Propane burns much cleaner and cooler than gasoline so the O2 sensors cant read it and often do not warm up enough to send a signal back to the computer. The computer then logs O2 sensor error codes relating to them being too cool and A/F ratios being to far off range.
I had a question about a possible schematics omission in my book and went to the local Ford dealership and asked them. They had me sign a paper with my name and address and then they gave me a full dealers service manual to borrow for a few days! It had every note, schematic, and factory change reference Ford ever released to the dealer repair centers in it relating to my exact model and year of truck.
I dont know if all dealerships will do that or not but locally ours do!