You have an external reg? They will. You need to ground the regulator better.
thanks, i fixed the problemWhat I did was to make a jumper w/solered connections. It is connected to a corner of the reg and to the body. Then, I cleaned the battery neg cable at the engine and then made a new, heavy duty ground wire (#10 AWG) with solered connections from the bat neg post to the rad support.
That fixed my wiggle and likely any other furture issues. A gound wire from the reg to the battery would be another quality repair.