I too have been working on my wiring. I found this "Fuel Pressure Switch" on the schematic, but I wasn't able to locate it on my truck. I figured it was something to do with the fuel system (because of it's name), so I searched the entire fuel line, from the than to the injector. I never did find this switch or where it was supposed to be. Thank you so much for posting the extract from TM 9-2320-361-20. Once I know where to look, I went to my truck to see if I could find it. It is not present on the secondary fuel filter housing, so I guess I don't have this part.
The replacement harness that I purchased is not the same as the one in my truck as it doesn't have the integrated plug for the turn signals. I haven't searched the harness for wires 74A and 74B, which are supposed to go this switch. Now, I am wondering if I need to add this part, or if it was removed from the M35A2's later in their life. Is this part necessary? My truck seems to run fine without it, but....
Thoughts, anyone??
Found where it is supposed to be but I don't have one. So I'll either add one or hook the wires together after I ring them out. To be fair this truck has had a lot of electrical mods done to it. 2 - 24v/12v converter , after market heater and defroster, dual tanks, battry ground disconnect, lots of LED lights. None of it done very...good. So now is the time to fix it all!
Thank you for posting the TM data that shows where this switch is supposed to be and the starting system wiring diagram...