can anyone help?int lights dont work and rear heat question

Si I bought a 01 caravan a couple weeks ago and it is putting me in the poor house.I have fixed a ton of problems but Im need help with 2 problems.The first one is none of the interior lights work at all,I think its either the light switch or the bcm.Any ideas?Also when I got the van somone had bypassed the reat heater core.I have 3 metal pipes behind the engine that should have hoses attached to thenm but they dont.I dont know where they go,does anyone have a picture or advice?Thanks