Lots of things can make them blink. Before sinking more money into switches, make sure you go over ALL the connections in the headlight circuit. The connector near the battery sounds like a potential problem. Another bad connection spot is at the bulk head connector where the wiring passes from the dash to the engine compartment. It is not uncommon to find that connection corroded green and burnt up. When a connection is nearing complete failure, it can blink the lights as the electricity struggles to bridge the increasingly burnt up wire and/or connection. Of course, the more this happens, the hotter the connection gets and the worse it burns. The same problem happens at the headlight switch. As said above, if the switch burns up, it can also damage the bakolite connector on the harness. If the connector is melted or damaged, replacing the switch itself and plugging the damaged connector back on a new switch will not solve the problem. Doing this could also cause the new switch to heat up and fail. BTDT!