What do you mean by "then they stop"? The gauges and dash lights stop working or they stop flickering?
There's two things to look at for what you described. The first is the typical loose and corroded battery cable connections. Second, follow the smaller positive battery wire to the under-hood fuse box and be sure that connection is clean and tight. Next, follow the smaller negative battery wire to the body and be sure that one isn't rusty.
Also, don't overlook a failing battery. A professional load test will check for that.
Saturday, May 2nd, 2015 AT 10:05 PM