Anti Theft System

The constant blinking of the red anti-theft light on the dash and the van not starting can indeed indicate an issue with the vehicle's anti-theft system. In some cases, the system may have triggered an immobilizer or anti-theft mode, preventing the engine from starting. Since you don't have a remote for the van, you may need to try a few troubleshooting steps:

Check the Battery: Ensure that the battery in the van is fully charged and in good condition. Low battery voltage can sometimes trigger the anti-theft system.

Lock and Unlock the Doors: Manually lock and unlock all the doors of the van using the key. This can sometimes reset the anti-theft system and allow the engine to start.

Try a Different Key: If you have a spare key for the van, try using it to start the engine. Sometimes, a faulty key or transponder can cause issues with the anti-theft system.

Disconnect and Reconnect the Battery: Disconnect the battery for a few minutes and then reconnect it. This can reset the vehicle's systems, including the anti-theft system.

Check the Owner's Manual: Consult the owner's manual for any specific instructions on resetting the anti-theft system in your particular model of the Chevrolet Venture.