Soak the connector with some penetrating oil (like WD-40 or PB Blaster). Wait a few days if necessary and wiggle it a little. Any oily residue can be cleaned off with alcohol or naptha. Another approach would be to cut the wires off 2-3 inches away from the connector and splice them back together later. It's going to be nearly impossible to do the circuit board repair under the dash.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!