1995 Buick Riviera headlights not working right

Electrical problem
1995 Buick Riviera 6 cyl Front Wheel Drive Automatic

I replaced the steering column in my 95 Riv and used a new (used) wiring harness from the column I bought. At first the cruise control wouldn't work. Then the low beams quit. Finally the high beams quit also. To get by, I hooked a temporary toggle switch to the low beams. I am ready to fix it for good and respliced the headlight wires the way they should be but the low beams wouldn't work. When you turn the lights on the highs stay on and when you pull the dimmer the lows flash but won't stay on. I got a wiring diagram from you guys already but everything looks ok. To be sure, I put the old harness back in and it is still the same. I really don't know what to do as I am not an auto electrician. Is there anything you can tell me to do before I fork out $350 for a new dimmer switch? I am in great need of this vehicle right now but I can't use it with no low beams. Any help would be appreciated. Thank you.