Ford Repair: SRS warning light, door ajar light, and interior light, ford ranger xlt, 2002 ford ranger xlt


Question
I have a 2002 Ford Ranger XLT 3.0 with barely under 56000 miles on it.  For about a year the door ajar light has come on or stayed on randomly.  Recently, the interior light has been staying on with it for odd amounts of time.  The day after that started, the SRS light began to flash (which it has never turned on, even thought I have turned on/off my airbags at times, and the manual says it is supposed to flash when I do).  Over the past few days, the SRS light would flash, stay lit, or turn off on a whim.  Now, it is constantly lit, and today my speedometer decided to take a vacation (as in no longer works).  Im assuming there is an electrical problem, and I was just wondering if you had any ideas of where it might originate and how difficult it might be to fix (as in: I probably have to go to the dealer because its electrical and the SRS, so how long will they make me suffer and how much might I have to pay for them to do it)?
Thank you in advance for any ideas.
Brandy
P.S.> It is an automatic trans, no power locks or windows (first thing to break, too expensive to repair!), basically standard everything else but the stereo.  Most recent repairs were made in December after an accident where the transmission cooler got smashed and the bumper was bent down around the wheels.  The current problems started within the last few days on a road trip to Vegas.  

Answer
Hello and thanks for the question...I'l try to help.
I hate to say it but you're right as far as bringing it to the dealership. It sounds like a GEM (generic electronic module) problem. It might need replacement OR reprogramming.
As far as cost....I couldn't tell you....I only fix them.
Hope this helps,
Erik