I have a 1990 chevy caprice having problems. With when i start. It up then it cuts off try to trun it back on nothing happens. This part that im going to sjow u is the problem what do i do

Without a little detail. Il gonna guess thats the main bulkhead connector at the firewall? As shocking as it may sound, alot of cars have alot of wire harnesses with large groups of wires, and they mostly all look similar.
When you say its the problem, that leaves a large amount of gray area. If it IS in fact the problem, then the nature of the fault determines the proper repair. if the connections are green or rotted from water intrusion, depending on damage level it might simply need a good cleaning (disconnected, both sides male and female) and perhaps retension the pins and it would be fine. IF that is all that is wrong.
If you have a burned wire(s) issue, then the bu8rn that happened at that connector may be caused by poor insulation in that connector, or it could be a short somewhere else that had high resistance at that connector (loose or dirty contacts as described above) and that connector simply melted from the excess heat/amperage...but the original cause may be inches or feet away from the connector.
Wiring is one of the most poorly serviced areas of modern cars. Nobody generally pays it any attention till there is a failure, and when that happens, often a problem that started in 1 small spot has spread,, or damaged other components and will require significantly more time to repair and determine original cause to prevent it from failing again.
a better description of the perceived fault would be helpful, and the symptoms including how often, conditions leading to its first occurance (if any) and why you believe that connector is "The problem".