99 F250 Dash Dead or Clicking Will Not Start

[casimirblue]

My son has my 99 F250 4wd now. 330,000 miles. A few weeks ago he claimed the batteries were dead and it would not start. I had him charger up and went out and checked it 10 or so minutes later. The charger draw was minimal at less than 1 amp. I then disconnected one battery to split the circuit. Same result. Checked both batteries with a volt meter good at 11.5 to 11.8 v. Next or finnally went in th cab and turned the key. Nothing, everything is dead, no dash lights, buzzzerrs, or dome light. I then while getting a manual out to check fusses messed around hooking and unhooking batteris and measuring voltages and turning switch on and off. At this point the dash started clicking like a relay cylcling. Then i hooked and unhooked batterires again (just fishing). At this point I heard the little vacuum pump running(had left key on) and Looked in cab and everything looked normal. Truck Started. So instead of looking further I ignored problem hoping it would never come back. Son is now stranded at QT. Anybody got in ideas. Thought it might be a battery savr relay but I don't have a diagram.

Thanks
James

[jcs]

that 11.5 to 11.8 volts is to low those batteries should have a good 12.5 or better

[casimirblue]

Replaced Starter and new batteries. Appears to be the problem. Didn't think it was but one must have killed the other. First starter in 300 and whatever thousand miles.

Thanks
James

[matter]

what about the alternator? did you check that......

[K9diesel]

After recharging and you only have 11.5v, one or both batteries are dead! It's possible they are at the end of life, bad terminals/wiring, or simply have a shorted cell. Looking for 12.6v minimum without the vehicle running.

[quadrace13]

clean all the terminals.... if everything came back to life after you reconnected the batts, you got a loose connection somewhere, brush everything down, clean it real good...