'94 LeSabre is probably a 16-pin DLC. I'd wager a small beverage on that one.
Regardless, a proper scanner will access it, either a Tech (Vetronix) or MT2500 (SnapOn), and with the appropriate adapters should communicate BOTH WAYS. If there is no 12VDC power at the 16-pin DLC (Pin 16), check fuses. The 12-pin DLC uses external power, so it is a non-issue.
After having spent so much time on parts replacing, a diagnosis is going to be the best and fastest solution. Your brother at Ought-Tow-Zone is not likely going to be able to help, since I have seen none of them with the appropriate scanner to communicate with your vehicle. They don't even offer one for sale, so they likely don't have one to use.