Freightliner Electrical/ Low Voltage

I have a 07 Columbia that has had electrical bunk problems. The low voltage switch under the dash was wired backwards. I wired it with the in going to the in-side and out to the out-side. Now, the ISO on the fuse box is powered but it also powers the ignition. So, I can't turn off the ignition. Has anyone seen this? We have not tried to replace the low voltage switch yet but when bypassed it does this. Any ideas would sure help.