93 suburban starter and heat trouble

My 93 will not start or even turn over with new battery in it. Icant figure out how to take the starter out because it has a sheild by iot and I can't tilt the starter at all anyone know how to take it out? And also the front heat in it works great nice and hot but the rear heat blows cold heat all the time, any suggestions please. Thanks Rick

I have a 94 and had the same problem with cold air at the rear. What I found was that in the engine compartment there is a "Y" that routes water from the engine to the front and rear heater cores. The "Y" has a very small hole in the part that leads to the rear. This hole had gotten plugged up with a small piece of something, thereby not allowing the water to flow to the rear. Whatever you do, do not enlarge this hole as the front heater will not get as hot and the rear will be extremely hot ( I know, I did this!).
Hope this helps.