1990 Legacy won't start

I just replaced the engine in a 1990 subaru legacy but it wont start. I did a compression check (good compression) Its getting spark to the spark plugs. Its got fuel pressure to the injuctors, my question is what (amperage?) Power do the injectors have to have because when I tested them by hooking up test light to neg and finding power then hooking test light to other side of terminal and poss. Turned engine over the test light lights up but is very very dim. Thats why I'm wondering if they run off lower amperage, (voltage?) If not why is the light so dim and will that keep the engine from starting