2003 D12 cuts out then back on

Hi Guys,
I have a 2003 VNL 420 with D12 465. My problem is that the motor will cut out on a rough spot in the road and then cut back in. It has never completely stopped. Just cuts out and then cuts back in. I don't loose cruise or any other electrical parts. When slowing down with the jake, the jake will cut out and then cut back in. I have checked fuse and wire at the battery, ignition switch, wires that loop under the steering column for broken wires, cleaned all ground wires inside and outside of the cab. So far have not found what is causing it. It starts and runs good, only does it on a rough road.
Any ideas will help

 

I found out what was wrong with my truck. The sockets that the engine relays plug into in the fuse panel under the dash were loose.