Heater Core Replacement--A/C car

I'm in the process of trying to replace my leaky heater core but having trouble figuring out what all needs to be disconnected and where the screws are that hold everything up. Every time I look under the dash all I can see is wires, duct work, and cables, which makes it hard to see how it all comes apart. I've looked in the shop manual and tried following the steps, but I always get stuck trying to find the screws or parts it's talking about.

I found a thread where a guy took pictures of everything and all the steps, but it was for a non-A/C car and looks pretty simple. I've never done anything with air conditioning, so for instance, "Disconnect the wiring from the A/C thermostat (icing) switch" doesn't help me much when I'm not sure what I'm looking for.

Anyone have any tips or pics that might help. I just got the new intake and carb on the car and the heater core started leaking, and I've been itching to take it out and see how it runs, but gotta fix this first. Thanks for the help.
 
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Heater Core Replacment

You will need to disconnect the hoses to the to the heater core in the engine bay, will help if you drain your radiator too. There are some nuts on the fire wall that hold the box in place, you will need to remove those. You will need to disconnect all the linkage to the heater box on the inside. Once that is done you should be able to remove the box w/the heater core. Be careful, 40+ year old plastic is brittle and breaks easy. Disconnect the negative battery cable before you start. It's a pretty simple job, just be careful with your box.
 
I got it all back together yesterday and have given it a good test drive a few times. It was actually warm enough to roll the windows down. I will get the A/C recharged next weekend. I've also gotta get some stiffer shocks for the rear. When I hit low spots the rear tires rub. This was really the first time I've driven the car since I replaced the rear suspension with the mid-eyes. Thanks for the help.
 
I got it all back together yesterday and have given it a good test drive a few times. It was actually warm enough to roll the windows down. I will get the A/C recharged next weekend. I've also gotta get some stiffer shocks for the rear. When I hit low spots the rear tires rub. This was really the first time I've driven the car since I replaced the rear suspension with the mid-eyes. Thanks for the help.


I need to go through this as well to fix a leaky heater core in my Fastback. What do you need to do to get the heater box out?

Thanks,

Andy
 
I sent him a message with most of the steps, unless I forgot something. It is a lot of steps and typing. BTW 2+2, I got my heater hoses figured out. Thanks for the diagram. I'm running 17x8 Foose Nitrous all the way around. 245/45/17 on the back and 205/40/17 on the front. I replaced the rear leaf springs and shackles a few months ago with a grab-a-trak mideye spring. I ordered the wheels and tires a while back, but they were supposed to fit and were the correct backspacing and zero offset. The 245/45/17 on the front hit the front of the fender so I got smaller tires for the front.
 
heater core 1989 mustang

you know i was going to replace heater core 1989 mustang lx and looked at new heater core now why cant a hole be cut in firewall and remove old core and instanll new heater core