electrical problem...sometimes

only when cold this blazer has no digital odometer, PRNDL isnt lit up, 4x4 wont enguage, radio doent work, a/c and fan controls do not work. but once the truck gets warm everything clicks at the same time and runs awesome

the vehicle is a 2000 chevy blazer with 136000 on it, 4.3 litre, and an aftermarket radio in it, dealership couldnt find any grounding isuuses or couldnt tell me what is wrong with it

please help

only when cold this blazer has no digital odometer, PRNDL isnt lit up, 4x4 wont enguage, radio doent work, a/c and fan controls do not work. but once the truck gets warm everything clicks at the same time and runs awesome

the vehicle is a 2000 chevy blazer with 136000 on it, 4.3 litre, and an aftermarket radio in it, dealership couldnt find any grounding isuuses or couldnt tell me what is wrong with it

please help

Acting up cold and working warm.

When it is acting up.
Check all electrical wiring and plug in and connections.
You are losing 12 volt feed or ground some place.
Get a good volt/ohm meter and good wiring diagram and start at battery and cable ends both + and - and work onto fuse box and threw ign switch and onto what ever is acting up.