What is the A/C amplifier? I just got my AC up & running after 12 years of not using it,I replaced the: Accumulator (drier) Condenser Evaporator Expansion Valve had new hoses made with new fittings (rerouted all hoses) & polished out all the fittings also replaced the tensioner pulley & belt I bought a gauge set up & vacuum ( compressor driven ) so I could recharge the system, ( changed to 134A) all went well,works great. Got most all on line!!
It's the control box for hvac systems in cars or trucks should be able to score one on eBay they often show up on there sometimes