Starting 3 days ago my 86 Bj70 with 3b had trouble starting. It would crank really slow and not start. I noticed my oil pressure was low so I changed out my oil (Manual said that was a possible cause) and then waited a few hours and tried to start again. One of my batteries is at 10v when the engine is off of that makes a difference but I don't really want to bring it to the shop unless I have to. Any help would be appreciated, thanks in advance.