Engine not cranking - starter?

Looks like you are on the right track. Check those same wires when it will not start. If it does not start and you get battery voltage at solenoid wire then your starter is defective. If no power then check your starter relay.

That relay that JIS001 referred to is in the "power distribution center". Swap it with an unimportant exact twin as a test.

I have a suggestion too.

Temperature and/or moisture might affect his suggestion or mine (especially mine).

Here is mine, see this long boring link with pictures at the end:

https://www.2carpros.com/questions/1996-chevrolet-tahoe-wont-start-sounds-dead-battery-jumpbox-get-same-reults

Be sure you return here with good news.

The Medic

Cranks but no start condition-do below to determine whether it's fuel or spark issue:

Get a helper disconnect a sparkplug wire or 2 and ground it to the engine at least 3/16 away from ground -have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/COP/coil packs, coil's resistances, distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it.

Welcome to 2CarPros.

If moving some wires around helps, then you must have a bad connection. The first thing I suggest is checking the battery terminals. Make sure they are clean and tight and free of corrosion.

Here is a link that may help:

https://www.2carpros.com/articles/everything-goes-dead-when-engine-is-cranked

Let me know the results or if you have other questions.

Take care,
Joe

Check battery for condition including load test first. Then you can check charging system at same time. Then next time it doesn't start have an assisntant try to start it an dyou hit the body of starter with a hammer. If it starts then the starter is bad.

Take the battery out and go to either a tire store/autoparts they do for free

Yoyu;ll need to get the cooling system pressure checked for a head gasket/leak etc. If stillnot starting, check fuses and starter relay in power dist center if the starter clicks or makes noise then it's probably the starter is bad auto parts can test that as well.

Good morning,

Did you get new keys with the replacement cylinders? You should have and they should be programmed.

Below is the procedure and description for programming the keys.

Roy

Two programmed Sentry Key transponders are included with the Sentry Key Immobilizer System (SKIS) when it is shipped from the factory. The Sentry Key Immobilizer Module (SKIM) can be programmed to recognize up to six additional transponders, for a total of eight Sentry Keys. The following "Customer Learn" programming procedure for the programming of additional transponders requires access to at least two of the valid Sentry Keys. If two valid Sentry Keys are not available, Sentry Key programming will require the use of a DRB scan tool and the proper Diagnostic Procedures.

Customer Learn
1. Obtain the additional Sentry Key transponder blank(s) that are to be programmed for the vehicle. Cut the additional Sentry Key transponder blanks to match the ignition lock cylinder mechanical key codes.
2. Insert one of the two valid Sentry Key transponders into the ignition switch and turn the ignition switch to the On position.
3. After the ignition switch has been in the On position for about three seconds, but no more than 15 seconds later, cycle the ignition switch back to the Off position. Replace the first valid Sentry Key in the ignition lock cylinder with the second valid Sentry Key and turn the ignition switch back to the On position.
4. About 10 seconds after the completion of Step 3, the SKIS indicator lamp will start to flash and a single audible chime tone will sound to indicate that the system has entered the "Customer Learn" programming mode.
5. Within about 50 seconds of entering the "Customer Learn" programming mode, turn the ignition switch to the Off position, replace the valid Sentry Key with a blank Sentry Key transponder, and turn the ignition switch back to the On position.
6. About 10 seconds after the completion of Step 5, a single audible chime tone will sound and the SKIS indicator lamp will stop flashing and stay on solid for about three seconds to indicate that the blank Sentry Key transponder has been successfully programmed. The SKIS will immediately return to normal system operation following exit from the "Customer Learn" programming mode.
7. Go back to Step 2 and repeat this process for each additional Sentry Key transponder blank to be programmed.
If any of the above steps is not completed in the proper sequence, or within the allotted time, the SKIS will automatically exit the "Customer Learn" programming mode. The SKIS will also automatically exit the "Customer Learn" programming mode if it sees a non-blank Sentry Key transponder when it should see a blank, if it has already programmed eight valid Sentry Keys, or if the ignition switch is turned to the Off position for more than about fifty seconds.

Try resetting security system if no manual look online for your car. That is probably what is wrong. If it still wont start with a reset then have a mechanic scan for codes as there may be a problem with security system.