Hey guy/gals...my dodge radio only plays usually in AM mode..but sometimes when i hit a bump it will play in FM but only for short periods of time..what's the problem i'm having thanks for the input.....

Hey guy/gals...my dodge radio only plays usually in AM mode..but sometimes when i hit a bump it will play in FM but only for short periods of time..what's the problem i'm having thanks for the input.....

First guess is something with your antenna.

Hey guy/gals...my dodge radio only plays usually in AM mode..but sometimes when i hit a bump it will play in FM but only for short periods of time..what's the problem i'm having thanks for the input.....
I'm thinking the AM/FM selector switch, or some circuitry right behind that in the radio. If the radio actually plays AM and FM stations, it's whatever selects between the two decoding circuits that is at fault.

It might be less expensive to get a new aftermarket, or try your luck at Ebay or a junkyard.