Got a 2000 model F650 with a Cat diesel and 7 spd manual. I can't remember the engine size. I know my Brand X has a 3116 Cat. Any way I parked for lunch today with everything working great. Came back from lunch it will not turn over. Turn the key on depress clutch turn the key everything quits working. The radio, dash lights air buzzer just like you pulled the cables off the battery. Switch it off and try again. Turn key to on engine lights, radio, buzzer all come on like normal. Turn the key to engage the starter everything goes off ,no start. I checked the fuses and relays nothing appears wrong. Tried jumper cables at batteries; nothing!!!!

I need some ideas to check before I call a wrecker and haul it to the shop. None of which I can really afford with our construction busunees down/none existent. Any help would be appreciated.

 

First thing to check is battery and cable connections,both end of cables
could be a bad battery but sounds more like connections

 

Ended up being a small amount of corrosion under the negative post of both batteries. Everything was tight, so I pulled the cables and checked the voltage which checked good. Spotted a little buildup under negative posts. I cleaned all 4 post and connections. Cranked like a champ ever since, hot or cold. Thanks for looking.

 

But for reference, it's a 3126E. 7.2 liter.