joebaker82

Truck would not start this morning. Go to crank it, all power shuts off. No interior lights or anything. Its happened twice before. First time replaced batteries worked fine after that for a little while. Second time it happened I figured maybe starter after the clicking noise it makes. Usually disconnecting batteries fixes it for a little while. 2509 is the code i got awhile back. Any ideas? I disconnected it several times today. Will not start at all.

6.7L MegaCab

I would check to make sure the cables going to both batteries are not corroded anywhere from the alternator to the drivers side battery. Check for corrosion or loose connections going to the PCM. Do you have the sentry key system? Could possibly be the key itself-but I think it is a power issue.

Hopefully this helps a little.

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6.7L MegaCab

1. Check to make sure connections are tight and free of corrosion

2. Both batteries above 12 volts?

3. Open Fused B+ to ECM
--disconnect ECM harness connectors, turn on the ignition
---measure resistance between the positive battery post and the ECM supply circuits pins 20, 30, and 40.
----Less than 10 Ohms? If not, repair the circuit

4. Open Ground Circuit
-- measure resistance between negative battery post and the ECM ground circuits pins 21, 49, and 50.
---Less than 10 Ohms? If not, repair the circuit

5. Battery + Shorted to Other Circuits
-- Measure the resistance between the ECM supply circuits (20, 30, 40) and all other circuits in the ECM harness connector, except other supply circuits.
---Is the resistance greater than 100k Ohms? If not, repair short in engine harness

6. Return Circuit Shorted
-- Measure the resistance between the ECM return circuits (21, 49, 50) and all other circuits in the ECM harness connector, except other return circuits.
--- Is the resistance greater than 100k Ohms? If not, repair or replace engine harness

7. Battery + Shorted to Ground
-- Measure the resistance between the ECM B+ supply circuits (20, 30, 40) and ground.
--- Is the resistance greater than 100k Ohms? If not, Repair Battery + shorted to ground.
---- If YES, then let us know and I or someone else will post up more info.

joebaker82

Thanks for the help. I will see what I can come up with