Toyota Repair: 1999 Corolla staying started, geo prism, ground connections

Question
Recently, we had a rebuilt corolla engine installed in our 1999 Geo Prism.  Currently, the car stalls immediately when you put the headlights on, however, if you remove the relay, the car stays started (pretty much, stalling and restarting with a little trouble).  However, with the relay out, the headlights won't work, the brake light blinks at the same time as the left and right signal, and the air bag light is on.  We have tried having the relay replaced but it still will not remaining idling if you turn on the headlights.  Do you know what could be the problem?  Our mechanic is stumped.  Also, as I don't know if this has anything to do with it, the A/C will only go on if you have the setting on "High", otherwise nothing. Thank you.

Answer
Something happened while the engine was replaced, possibley some of the engines wiring was not reconnected or some of the ground connections are not connected, this is an electrical problem that was created when the engine was replaced because it wasn't there before, is that not correct? You should have the mechanic that installed the engine recheck all of the electrical wiring that was removed when the engine was replaced, there is something disconnected somewhere, or some wiring was damaged.