Coolant leaking when turning heater or A/C on?

The A/C stopped working a while ago and I think it is the compressor because it made a lot of noise before going out, so no A/C.

Usually when I turn the Fan on, the steam will start coming out almost instantly but by then it is so steamy and makes it impossible to pin point the leak, and I usually stop the fan and everything goes back to normal, no leaks, the weird thing is that this will happen every time I turn the fan on, (there are no noticeable leaks before or after using the fan).

In an unrelated (or maybe related) incident, yesterday I had my truck towed from the road because I started seeing steam coming out of the hood (again). Let me say I have had every possible coolant hose bursting at least once with this truck.

Today I pressure tested the coolant system with my hand pump and I detected a leak coming out of the manifold. I will be ordering and replacing it when possible. But the question still remains. Why can't I use the heater on this truck?

Thanks for the reply, I will do as you advice as soon as I get my hands on the repair I mentioned before, which brings me to another question, When I did the hand pump pressure test, I saw coolant dripping from a small crack under the exhaust manifold, this means I have a bad head gasket right? I should not have coolant in there.

Let me try to clarify, the part that was leaking when I did the pressure test was the exhaust manifold itself, right before it attaches to the beginning of the muffler pipe, then after this I noticed that the coolant was leaking with my truck just parked there and no pressure whatsoever. See pic I took from under the engine. Thanks

Thanks for following up with my questions, yes so coolant should not be leaking out of there, so how do I find what is the issue here? (Cracked head or head gasket) before I spend any money,
And to answer your question, that one is the heater hose.
I attached it.

You were right! The heater hose was cracked, (the hose you saw in the pic) there was a burned spot on it. This was causing the leak that made it look like it was coming out of the exhaust manifold.

I also replaced the heater control valve since it has leaked in the past and it's been a while since the last time it broke (like 3 years)

I will keep an eye on it next time I try to use the defroster, maybe I can pinpoint the leak.

Thanks a lot for your suggestions.

Sure thing I will let you know. Thank you, have a nice thanksgiving as well!