Does it have the automatic temperature control, or manual controls? If it is automatic, the control module may have fried
All the cars I have seen with a 3.1 have "dog bones" at the top front of the engine that you remove, allowing the engine to rotate forward so you can access the back plugs and firewall, etc.
The blower motor is most likely behind the engine on the firewall. It is the most likely part to fail.
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