Make sure there is the correct voltage going to the dist. On yours I think you should have about 8 volts not 12. There should be a resistor wire to cut the voltage down.
Probably lack of die electric grease under the mounting surface of the module. This special grease keeps the module cool & lack of it could cause the module to overheat & burn out.
Ignition switches and body control modules are issues on these cars.
You should check the pick-up coil, it can short out the modules. I have ran into this problem before and was a the end of my rope. I found a pamphlet at the auto parts store and read through it and came to the conclusion that the pick-up coil was shot, replaced it and never had to put another module in. Probably lack of die electric grease under the mounting surface of the module. This special grease keeps the module cool & lack of it could cause the module to overheat & burn out.
It would have electronic ignition, no points.
A bad ignition module.
Ignition module in the distributor.
The 1991 Blazer has a current draw causing the wire to burn. You will need to trace the wiring out to find what is drawing too much current.
test ignition coil,ignition module,pick-up coil,electronic spark control,and knock sensor
I would expect that the power for the fuel pump would be supplied through the ignition switch so I would start there, that is check the ignition switch.
Probably ignition switch. Have it checked out.
I would replace the ignition control module that's in the distributor.
I would suspect a failing ignition control module.
Because it has HEI (High Energy Ignition).