03’ International 9900i A/C not cooling well

[DVT873]

How high is the head pressure? These have a high pressure switch that will turn the engine fan on. Is the AC compressor cycling correctly? post VIN. With it I can find some detaled info. Is it a Cummins? Vaguely remember some problems like this but might have been a bit older. Per a pretty good Cummins guy the ECMs would "drop" the fan cluch programming. High pressure AC switch would send the signal to the ECM that in turn ran the fan. He's long dead and that was close to 20 years back. And I don't see a lot of of 9900i's. ...One thing to try. Find the fan solenoid. It should have 2 wires. If it is bolted to something metal unbolt it and secure it to something non metallic like a harness bundle. Peolpe don't beleive this but I have personally seen this be a problem several times over the years. Easy and cheap to try. The mounting loop around the solenoid is supposed to be insulated from the body but not always.