The #5 Rec charges the Capicator, and if it has any charge it is probably good. If it was weak it more likely would let you run with the wheels off of the ground but trip under loads. When the Cap goes bad usually it is leaking oil, or I have had the connection from the post to the material inside break as if someone turn the stud trying to get the nut off and it is just an open. I think twice out of hundreds of time it was the coil the one where the negative leads all tie to. It may also be the card is not turning on the 2 or 5 if the card is bad, the plug from the card to the 2 and 5 may have a bad connection. It this was worked on before you got there well then then there may be a wiring issue. As a matter of fact the older Hyster manuals show going to the mounting screw and not the terminal on one of the recs. But in my experenice >90% of the time changing the 2 and 5 and its working.