99 navi and my scanner doesnt read codes

[b.a.voice]

Hey everyone, I have a 99 navi and when I hoop up the scanner to it, it doesnt read. I brought it to advanced auto parts and they couldnt get a read either so I had to bring it to a dealership. They got the readings from some "FORD" machine since my scanner wasnt working but what I want to know is how can I fix the scanner so I can know what the problem is with my truck. The service engine soon light has been on for 3 weeks. Thanks


B.A.

 

[TownCar]

..what I want to know is how can I fix the scanner so I can know what the problem is with my truck.
B.A.

What scanner do you have?