Truck turned over real slow yesterday morning on the way to the park and left it idling for the hour I was there, come home and the truck turns over just enough to start then won't fire again. Just cranks slow a turn or two and stops. So I figure it's the starter and I walk another one down to be rebuilt. Sawp in the rebuilt one and the same problem.Turns over real slooowww and then nothing.

Both batteries read 12.54 volts. I disconected the powerlead and hooked jumper cables directly to the stater while using a screwdriver to activate the solenoid: same results very slow cranking. I had the starter rebuilt by a place down the street, but I'm assuming that they bench tested it. What should I chek next?

 

i would say its your batteries.

 

Jumper cables to the starter may or may not make good enough connection to turn it over good and strong, works usually with gas engines but these draw a lot of amps. Best to get the starter tested again, the amp draw can be tested on the truck if you can get a tester.
Also, did you disconnect the battery cables and test the voltage separately. One good and one bad battery connectedly together will show 12+ volts, but not start or start real hard. Best to test each battery with the cables off, one may show slightly low voltage. Better yet check them with load tester, if you can borrow or buy one. If the batteries and starter are good start checking all the connections including where the negatives bolt to the block, somethings got to be not making connection.

 

I disconnected both batteries and tested them. Driv. side was 12.6, pass. was 12.2. I had another battery on a charger just in case and swapped it out for the 12.2 (it had 12.7). Same results.

Seems like there is a huge draw on the system. When the grid heaters kid on, the voltage drops to nearly 8 volts. Then the voltage is around 10 volts with the key "on".

Asuming I've got something suddenly drawing more power, how do I track it down?

 

Have you had your batteries load tested? Holding a voltage is one thing, but a load could drop em to no volts quick. What were you jumping the starter off with?

 

sounds a lot like the batteries...what is your idle at? Any difference if you give it a little pedal?

 

I t was thebatteries. One was only 1 1/2 years old so I'm a little bummed they were both shot.
Thanks for the help guys, I was to stubborn to see the obvious answer

 

Was just gettin ready to pipe in, but looks like you already got it figured out. You should always load check a battery. Just checking for voltage does not always give a tell-tale sign of being bad. As you found out, they can have 12v, but not be able to hold a load. Glad you got it fixed.

 

Usually if you run one old with one new, the old one will also kill the new one. Best to replace them in pairs. I know it's to late now, but I figured it might help someone.

 

i would replace both batteries... when my grid heater is on it only drops to 10.8 - 11.2 volts.

 

im a , maybe next time i should read that WHOLE thread!

 

i recently bought two rv batteries for my rv from wal-mart, got em home and put them on a charger to "top" them off installed them....... two hours later they were dead.
i tested the elecrolite ,and one battery read O!
the other was ok

i couldn't believe it, a brand new battery is junk.
so any more i will have any new battery tested before i leave the store