No crank
 

2006 Cummins manual trans

Drove it this morning no issues.

Removed boost fooler -- back to stock for upcoming smog. Started fine.

Went to start 30 minutes later, nothing.
Voltage is good and doesn't change when trying to start
I hear a faint buzz when I turn on the key
The radio turns off in start position, which might mean the ign switch is okay
Found one Code -- P2509

Put boost fooler back in just in case, but no change. Think it might be a coincidence.

Found the OBD2 plug loose when I installed scan gage. Snapped it back in it's bracket. No effect on starting.

Next?

edit: installed new batteries two or three weeks ago. Passenger side had cooked. Been driven many times since then.

I recommend you thoroughly clean the battery terminals as well as the opposite ends of the cables. Most importantly, clean the grounds that connect to the body.

Well it won't be the connections at the battery because that would show up when I do voltage check while cranking at both the terminal and at the battery post. Doesn't absolve the other end of the cables though.

New clue. When I depress the clutch and turn the ign switch I hear a faint relay click from under the dash perhaps. With the clutch pedal up, I get no relay sound. I think that clears the clutch safety switch. And the ignition switch. I guess the next potential culprit is the relay itself. Is that a plug-in under the hood? Wish I had a shop manual.

Solved (for now)
 

It might have been the battery install. Autozone put them in gratis and in this case you get what you pay for. He failed to note there were two nuts on the terminal, an inner nut tightens the terminal and the outer holds on a ring terminal for optional wiring. So he tightened the outer nut and called it a day. I twisted it off by hand. On the other hand, my voltmeter said I had good voltage at that terminal during the attempted start, so dunno.

Possibility #2 is we got down and wiggled the yellow wire that runs the starter solenoid. Seemed okay. But after doing those two things, it starts normally. Can't say now which one did the trick, but the trick got done.

Voltage and current are two different things. You can have 12 (or 13) volts with a bad connection, and not enough current (capacity) to start the engine. A bad or improperly installed terminal as in this case, allowed the correct voltage, but not enough current to flow to the starter.

You can test it two ways, go to the starter and put a carbon pile load tester on the battery feed and pull some load on it. Or put a test light on the power feed to the starter and have someone turn the key if you loose the light then you know that you have the issue isolated.

I know what you're saying, but don't think it applies here. I had the voltmeter on the battery terminal when I tried to start the truck. If a bad connection had limited the current from reaching the starter, the voltmeter would have taken a dive. In my case there was no indication the starter was even trying to engage and hence no ripple in the voltage. It acts more like the solenoid wasn't getting activated. A few things could cause that, but now that it's working...gonna be hard to pin down.

Actually, no drop in voltage on the terminals says that there is a bad or no connection when the starter does nothing. Exactly where that occurs can be multiple places as there is more than just a battery terminal inline with the starter. With little or no current flowing, you wouldn't expect to see a voltage drop. You see a voltage drop when current flows. When one number changes, the other will always change with it. So when the voltage doesn't, that's a direct indication that no current is moving.

Having the same problems as you, crank but no start. My problem is looking like the tipm (totally integrated power module) which from what I gather is the fuse box/ block. The tipm controls everything from the turn signals to the starter solenoid and ecm. I threw the same p2509 code I would have that checked.

For the record my cables, batteries, and alternator, fuel pump, and starter all showed good voltage.

Hope this helps.

1999 dodge ram diesel wont crank
 

im new to the diesel world and my truck wont even crank! its 30 degrees out and it wont even crank,wont click or anything. just had the truck running yesterday just fine and came back to it this morning to nothing[verymad] new batteries and everything but its not saying anything. I even plugged the block heater in but I don't think that's the problem because the last time it was cold outside it would crank but I had to keep the block heater plugged in for awhile. Please help if you can.

Your TIPM controls the relay that starts your truck. A lot of problems with the 2006. Disconnect both batteries and let it sit for a while. Before hooking them up jump negative and positive cables together to suck the rest of the voltage out of the system. This should reset the TIPM and you should be able to start the truck again after you hook the batteries back up. If you are still confused do a search on TIPM reset. You can take it to a dealer and they will reprogram the TIPM to handle more amps before it trips again.

there were two nuts on the terminal, an inner nut tightens the terminal and the outer holds on a ring terminal for optional wiring. So he tightened the outer nut and called it a day.
This was the problem. Your batteries were NOT GOOD connected to your electrical system.