Auto Air Conditioning & Heater Repair: Evaporator, negative battery cable, backup power supply

Question
Hi David,
I was wondering if you could answer a few questions for me about a 1999 Ford Expedition.  There is a hole in the evaporator of the AC.  What is the easiest way to get to this part through the dash (will the whole dashboard need to come off or just part of it)? Also, how do I turn off the airbags?  
Thank you,
Megan

Answer
Megan,
I will give you the step by step that my online repair service gives me. If you can give me some advice. I also own a 99 expedition. How in the heck do we change the spark plugs closest to the firewall on the passenger side of the engine compartment. I have been fighting to find a way without having to take apart all the vaccuum lines and everything else. Ever do it or seen it done? Any advice is welcome. I wish the engineers who designed vehicles had to work on them sometimes.
As for the airbag. When you disconnect the negative battery cable, this starts the deactivation of them. However, the system does have a 1 minute backup power supply that may still deploy them if you do not wait for it to drain. My recommendation... play it safe wait 5 or 10 minutes before doing anything around the steering column or dashboard that may deploy them.

I just breezed through the instructions for removing the evaporator, and it is quite lengthy. The lengthy part is discussing the removal of the instrument panel. If you send me an email address in a follow-up to this question (mark it as private so it doesn't get posted) I will send you the full directions in a powerpoint or word doc. The service doesn't allow me to copy and paste from the site and If I try to type it, it will take me about 2 hours to type it all out. I assure you that I will use your email this one time and never again.

Than kyou for your question, and I await your follow-up. During the process or in the future after this is complete if I can be of any more assistance, please do not hesitate to ask. If this and the follow-on information is found to be useful, please remember to rate this answer. Thank you again  and good luck in everything.