Ray L Westgerdes

Hey guys. I've never had this problem so I wanted to get on here and hope I get some good input. I have a 1998 cherokee limted. Just put in a heater core last week. I went to get in it today and I had no power to the dash. The interior lights work, the blower comes on. Would could be. I literally just tired it off and was home for maybe 30 mins. The other day I had to pump the gas to get it started don't know if that's a cause. I triple cHecker all wires and connectors. Plz help thank you in advance