Hi, ERCJCC; It is very possible that you've blown a fuse. Check any fuses under the dash and the main power box under the hood. Otherwise, sounds like you've disturbed a connection while swapping stereos?
Recently we purchased a 2004 Jeep Liberty 4x4. The check engine light came on and we diconnected the positive on the battery it went away. Right after we plugged it back up we tried to install a jvc radio which we decided when it wasn't working maybe we needed to also get some other connectors for it mind you we lifted ebrake to do this as well. When plugging stock radio back up none of the radio parts work and neither does my rear defrost. After all of this the next day I noticed my mph gage stopped working. Can anyone tell us what we need to get and how to fix this my husband and I usually try to fix things on our own unless too complicated then we take it to the shop. Thanks in advance !