[pairodice]

It is really difficult to see where the water is streaming from - it looks like it is coming from the area above the two ping tanks in the front of the coach. Are there hoses for the heater core under the coach (I would assume not since there are four hose connections on the heater core.
Next question: IF the heater core is bad then can should I connect the 2 red hoses together (I would assume the red hoses represent HOT) and then the 2 black hoses together?

[Richard]

Ok,

There are two sets of hoses. One set goes forward to the heater core. The second set goes to the AH.

Identify which set is which.Close the supply line and return line to the dash. This is much easier than bypassing the heater core.

Fill the coach with coolant. And be done with it.