No dash or switch lights with the head lights on

Some of the resent posts on the topic made me pull the cluster gauge and test the rheostat with my multimeter. The dimmer switch is defiantly bad, so I decided instead of ordering the part and all of that jive; I would just bypass the rheostat all together and solder a wire in its place. When I placed the wire on the two prongs that had previously connected to the dimmer it pegged the temperature and fuel gauge. Is something wrong or do I actually need to replace the switch and stop being a cheap bastard?

1984 300D