spring box resistor or ecu

[stevelewis]

The first day 4 ac and the gremlins strike, 83 300sd 250,000k 134 conversion, worked great last year, new acc blower last year,fuse box upgrade last year, new acc unit last year,traveling about 45mph with ac on with high fan,wheel to full cold, out of no where the fan cuts to low, and then the smell of burning something. Turned acc unit off and went on my way. the smell cleared and the car ran great the rest of the day, 60 or so miles. I did a search and came up with two things,the spring box resistor and some ecu control box at passenger side foot well.If anyone has been down this road and can give me some advise as to how to proceed at this point I would be very greatful. Thanx steve