94 Jeep Cherokee Sudden Electrical Failure

About two weeks ago I had the front passenger headlamp replaced which required the battery to be removed first. When it was put back together, suddenly the warning lights would come on one by one (check engine, abs, airbag) and the tachs and electrical gage would go dead. Eventually all electrical went dead and the engine stopped running. We replaced the alternator and the battery and initially it started fine. Now it has started doing the same thing again, starts up okay and after about 10 minutes the warning lights are coming on again and all electricals go out, one by one. Please help! We are just about to lose our minds!

Thank you in advance!