97 ford windstal gl electrical issues

In my windstar (just over 200 000 km) I have gone through 2 alternators in 1 month my mechcanic is stumped. I have seen some things on line about a wireing harness in the steering column losing insulation due to some kind of abrasion. also the cruise control realese switch having issues. also (of course)
i have the intermittant engine warning light (will check MAF) and my mech told me of oxygen sensor codes that he found p140 i think...
As for the interior lights staying on (door ajar light on dash)I found that hosing all door latches (inside doors) with wd40 cleaned those sensors and stopped the problem 6 mths now no reoccurance..

Thanks for your help in advance

Perryh

If your battery is getting weak, it can place an additional load onto the alternator. Sometimes, it is worth changing the 2 as a pair.

thanks for that battery is ordered.

replaced battery still the same issue after 30 min or so the batt light comes on the alternator starts off at 14.2 vdc across the batt but as engine warms up it starts to fluctuate(sp?) down to 12.4 and all areas in between and then to 11.7 and lower as time passes have been recharging my batt with a trickle charger to keep it up is that harmfull?:banghead::banghead::banghead::banghead:
please help

all connections seem fine no visable breaks arghhh!!!!!!!!