A/C questions

[the missing link]

I can't remember exactly but on my 2000 9900 I had to replaces a control on the firewall , it was a black box with I think 4 lights on the side . It would turn the green one on for working and ect. If I remember correctly we switched it out with a new one to trouble shoot . But I know I cut the wire and jumped it across before the model and it would work . I will be home Sunday night and take a pic for you . If you follow the wires back on the compresser you will find it . I think drivers side firewall Apad control is what it's called if you have one. If you google it ,it will tell you blink codes ect
Hopes this helps