S10 Blazer - 1996 4x4 Problem

Very strange problem. To get my 4x4 to work I have to disconnect the battery for 5 minutes. When I reconnect the battery I can press the button and switch to 4x4. To switch it back off I need to reset the battery again. The switch itself is new and the little switch on the transfer case I replaced. I am not familiar with the rest of the componenets that make it work. Any help would be great.

1996 S10 Blazer

Frank.

there is a little vacuum switch up on the firewall (in the middle) check for 12volts on each wire. The switch will have to vacuum lines and a 2 wire connector. When 4x4 is selected you should have vacuum going to the diaphram under the battery trace the hose so you know which on it is. If vacuum is present does it get shut off when you select 2wd? If not then do this while in 2wd check for 12volts on each wire of the vacuum switch then select 4x4 and check for 12volts on each wire. do this by back probing the connector.