Blinker Problems
 

I bought a 2000 Jeep Cherokee Classic yesterday, on the way home following it noticed that when you use the turn signal the rear and front left all flash at the same time its not 100% of the time very random happenings maybe 1 for 6. Checked and cleaned contacts & grounds. Tried putting in a new relay this morning, it made it worse they all flashed. Checked for trailer wiring and it was fine as well. Has anyone had this problem or any ideas on how to fix? Thanks.

Thats odd. You said it has trailer wiring. Doe's it lead to a small box? like a module I've seen them malfunction and cause weird problems.