2011 Tahoe 5.3 LMG no crank. Pretty sure I've checked almost everything.

Andy Brown · October 10, 2019

I apologize for the novel, but here we go!

Alright, so 2011 Tahoe 5.3 LMG Flex vin 0, 158k miles, never given me any issues ever before.

Drove it up on ramps last night to get under it to just check everything before I tow a trailer over the weekend. All fine and dandy.

Go to start it to back off of the ramps-dash and running lighter all turn on. Turn the key to ignition and....nothing. If I try to remote start it, I just get an electronic noise.

Took the starter off last night and tested it multiple times at my work (advance auto) and my starter was super dead. Sweet, found my issue, right? Got a new starter. Put it on. Still no crank. No click. No nothing except everything else on the truck acts like it normally would when you turn the key.

I checked connection between the positive terminal on battery and the starter with a multimeter -just fine.

My battery is perfectly fine. Tested it multiple times now. Have a charger. Made sure it's fully charged. Double and triple checked.

Looked at all the applicable fuses I can think ofand swapped the starter relay with the ac relay (they are identical) and it changed nothing.

This then led me to believe maybe the ignition switch in the steering column was bad. Put a new one in today. Same exact issue. It changed absolutely nothing. Everything turns on but no crank and no relay sounds or anything.

Almost thinking that something isn't sending the signal to the little wire connector that is on the starter selenoid (attached to the starter). But I feel like I've checked everything that could block that.

I'm running out of ideas and I NEED (super awesome timing!) this truck to move from Lincoln to Omaha starting tomorrow ugh

Was wondering if putting 12v constant to that little plug wire on the starter solenoid may skip whatever is not sending the signal, which I guess would just confirm that there's no signal. I dunno. 8+hours into this so far. First time this truck has ever given me issues in 158k miles.

Also, no, it will not start in neutral.

Any tips would be awesome!

sefiroxx · October 10, 2019

The smaller wire in the starter is for the solenoid and is line for the start circuit. The larger wire is always hot and is the primary amperage wire.

Make sure truck is not in gear, use a short wire to jump the two wires, it should crank.

The start circuit is routed from ignition, through items like neutral safety switch, security and the relay.

Test the relay socket. Car on, not in start mode, one socket should be hot. If not, check fuse and wiring for socket. If not, a jumper wire put diagonally across from hot socket will provide power to solenoid.

Car on crank mode, second socket on relay should be hot. (This is the control circuit). If not, then check nss and security.

O_J_Simpson · October 10, 2019

Spark, fuel, compression and O2. Your truck is not getting one of them. Tell us and we will go from there.

BlancoSilverado · October 10, 2019

22 minutes ago, O_J_Simpson said:

Spark, fuel, compression and O2. Your truck is not getting one of them. Tell us and we will go from there.

It seems that the motor is not cranking, the list that you created wouldn't matter until the motor is turning.

O_J_Simpson · October 21, 2019

On 10/10/2019 at 3:37 PM, BlancoSilverado said:

It seems that the motor is not cranking, the list that you created wouldn't matter until the motor is turning.

That would be the compression part of it. Start with the battery and work toward the starter. If all still good the engine is locked up tight and...."That's all folks!" for the engine.