Starts for 2-5 seconds then shuts off?

Hi,

It's interesting the electronics work only with the engine running. Have you tried load testing the battery? With the engine running, we have the alternator producing. With it off, that is gone.

Let me know.

Joe

I checked the battery and lights get bright when it starts. I read something about a maxi fuse on the rail but not sure where that is check all fuses relays all test good .

Hi,

I reread your original post. Is the security light staying on or flashing when the engine does start for a few seconds? If so, try this as a test. Turn the key to the run position and wait for approximately 10 minutes to see if the light goes out. If it does, then start it to see if it remains running.

As far as the fuse question is concerned, there are no fuses on the fuel rail. Also, you indicated you can't retrieve codes. Check pin 16 at the data link connector. It should have power at all times. If there is no power, check the cigarette lighter fuse in the under-hood fuse box. If the fuse appears good, confirm there is power to and from it.

Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Pic 2 below shows the DLC. Pin 16 should have battery voltage at all times. Pins 4 and 5 are grounds. Check for continuity to ground if pin 16 checks are good.

Let me know,

Joe

See pics below.

first of all thanks for your help so far Joe, I think it electrical because my door lock don t work and window radio don't work when key is on position but blower, lights,turn signals,dashlight,power minors work but windows .and radio work for however long truck runs door lock work right last time truck ran now nothing all on same door control change it had same problem.

Hi,

It does sound electrical. Do me a favor. I want to look through different wire schematics. I need to know if it is a 1500, 2500, or which one you have. The 6.0L is offered in the 1500, but also the heavier duty trucks. I just want to make sure I'm looking at the right pics.

Let me know.

Joe

my truck is a Chevrolet Silverado 2500 not HD 6.0 L crew cab with 200,000.

Hi,

First, I need you to check the TCB fuse. This is a 10-amp fuse in the under-hood fuse box.

The TCB fuse powers the body control module which controls the electronics you are dealing with. See pics below.

When you check the fuse, make sure there is power to and from it.

Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Let me know what you find.

Take care,

Joe

See pics below.

fuse is good look fine no corrosion.

Hi,

Were you able to confirm there is power to and from it? If so, then we need to check at the body control module for power at the orange wire.

Also, consider scanning the can-bus to see if there are codes stored in the BCM that may point us in the right direction.

Here is a link that shows how it's done:

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

I'm still questioning a problem with the ignition switch itself. If you find codes stored in the BCM, it should help guide us in the right direction. Otherwise, it will become a guessing game.

Let me know.

Joe

hi Joe, check all things and all had power and ground my question is if you have wiring diagram how when key is on position how is it possible to have no power to three things but have them work for 2-5 seconds I'm going to try get codes when it run next but is there a wiring diagram than will help me also I can't believe I have the only truck this happened to.

Hi,

I would be happy to provide any schematic you would like to have, so let me know which you are interested in having.

As for your question, the idea that it works and then doesn't could be a weak connection at a connector or even a solder joint. It may (or may not) only handle the power for a short period of time. Please understand, that is only a theory.

Let me know.

Joe