No Crank, No Start. 2007 Silverado 1500 Vortec Max. HELP!

[04vqmaxsl]

Ok, I'm stumped! I've been trying to help my brother work on his truck for the last few days and I'm at a loss. It's a no crank, no start issue. Battery is only a few months old and tests fine (800CCA,) starter is only 2 months old and we've pulled it out a couple times to have it tested and it's fine. Positive and negative battery cables are also fairly new (last spring.) I've tested pretty much every fuse and relay in the truck that had to do with the starter, etc. My brother has tested the resistance on most of the cables and wires (battery cables, alternator, starter, etc.) Anti-Theft has been tested as well.

Now, here's the odd part. When the key is turned, the starter clicks, but it doesn't turn the engine... at all. About the only thing I haven't tested is to see if the engine is locked up (which would realy, really suck.)

Now, this is an L76, 6.0L engine. It has D.O.D and variable valve timing, so the issues may be different than the 5.3 or 4.8. Does anyone have any ideas? Any help is GREATLY appreciated!

[rhandwor]

I would use a 1/2 drive long ratchet and socket on the bolt for the crankshaft. You should be able to roll the engine over. Put a volt meter on the battery and watch voltage does it drop when trying to crank? Put a test light on the small solenoid wire does it get power when trying to start.

[j cAT]

Originally Posted by 04vqmaxsl

Ok, I'm stumped! I've been trying to help my brother work on his truck for the last few days and I'm at a loss. It's a no crank, no start issue. Battery is only a few months old and tests fine (800CCA,) starter is only 2 months old and we've pulled it out a couple times to have it tested and it's fine. Positive and negative battery cables are also fairly new (last spring.) I've tested pretty much every fuse and relay in the truck that had to do with the starter, etc. My brother has tested the resistance on most of the cables and wires (battery cables, alternator, starter, etc.) Anti-Theft has been tested as well.

Now, here's the odd part. When the key is turned, the starter clicks, but it doesn't turn the engine... at all. About the only thing I haven't tested is to see if the engine is locked up (which would realy, really suck.)

Now, this is an L76, 6.0L engine. It has D.O.D and variable valve timing, so the issues may be different than the 5.3 or 4.8. Does anyone have any ideas? Any help is GREATLY appreciated!

with the starter motor not cranking but the solenoid clicks sure this could be a seized up motor. my guess is the big cable from the starter is bad where it is at the battery. some times the starter bolts Loosen then this causes a bad ground. since you removed the starter a few times my guess is this and the connections are clean. next would be the starter solenoid connection this is the one that has NO wire to it just a short jumper wire to the motor armature. these do loosen and most people do not check it.

when you turn key to crank using a volt meter at the battery a normal voltage when the starter clicks would drop to 9 volts. if the voltage does not drop then the starter needs replacing . starters need a load when testing no load is not a true test as loose connections internally would cause this condition. also a sticking solenoid.

if the voltage drops a lot more than 9V then remove plugs see if the motor can be rotated. see if water/coolant comes out [head gasket] ...

[04vqmaxsl]

So, I just got back from working on it. It's not done yet, unfortunately! I tried a new starter to rule it out, and it didn't help. Engine isn't siezed up, turns freely as well. All connections on the starter are tight so I know it's not that. Tomorrow, I'm going to check for a voltage/amperage drop on the positive cable from the battery to the starter. If anyone else has any input on this, it's greatly appreciated!!

[777stickman]

An easy check for bad cables is this. Turn the headlights on bright. If they go out when cranking, you have some cable/connection issues.

Testing resistance on these cable tells you nothing about what they can carry as a load.

[04vqmaxsl]

The problem is that the truck doesn't even crank, all you can hear is the starter solenoid click.

[rhandwor]

Originally Posted by 04vqmaxsl

The problem is that the truck doesn't even crank, all you can hear is the starter solenoid click.

Put a volt meter on the main starter wire to the starter. If the battery is 12 volt and the voltage is 8 volt at the starter you have bad wire to the starter. Clean the ground wire at the frame.

[777stickman]

Originally Posted by 777stickman

An easy check for bad cables is this. Turn the headlights on bright. If they go out when cranking, you have some cable/connection issues.

Testing resistance on these cable tells you nothing about what they can carry as a load.

OK. Let me rephrase that to "when you try to crank".

[aleekat]

Have you put 12v directly to the starter?

[j cAT]

Originally Posted by 04vqmaxsl

So, I just got back from working on it. It's not done yet, unfortunately! I tried a new starter to rule it out, and it didn't help. Engine isn't siezed up, turns freely as well. All connections on the starter are tight so I know it's not that. Tomorrow, I'm going to check for a voltage/amperage drop on the positive cable from the battery to the starter. If anyone else has any input on this, it's greatly appreciated!!

so you must now have , with this info given, have a bad cable from battery to starter ,,,, the big fat wire !!! that was my first suggestion .. as was mentioned resistance don't mean much , when your working with 200 amps of load current..

[James170771]

Have same problem. Doesn't turn over. No click from starter. Lights and everything work but onboard dash volt meter for battery shows nothing. Had some corrosion on battery post so I cleaned. When I reconnected had a spark and now nothing. Was the only thing I did and the truck worked perfectly before that. Help please

[brcidd]

How does the ground cable to engine block look? is it tight and clean at block connection? Does it go directly to battery? corrosion at any ground connections?

[James170771]

Yes they are good. windows, door locks, dome lights don't work. It makes no sense. works. Diagnosis from machine says no connection to BCM....fuses are good.....

[rhandwor]

Originally Posted by James170771

Have same problem. Doesn't turn over. No click from starter. Lights and everything work but onboard dash volt meter for battery shows nothing. Had some corrosion on battery post so I cleaned. When I reconnected had a spark and now nothing. Was the only thing I did and the truck worked perfectly before that. Help please

Check if you blew a fuseable link when you had spark.