CJ7 Electrical Issue

[Peak]

So me and my uncle are preparing for a trip and lately he's been having some electrical issues in his CJ7. Whenever he goes over a bump or dip the radio and cb shut off and reboot a few seconds later. Also we noticed the horn won't work during that time either. Radio and CB are ran straight to the battery and ignition switch. The horn is aftermarket but runs off the factory horn wiring. Any ideas on what we should check first before we dive in to it?
Thanks in advance.

 

[WJCO]

Check for loose major grounds, check for loose battery terminals.

 

[Peak]

Check for loose major grounds, check for loose battery terminals.

Will do, thanks.