Your comment starts with overheating with the a/c on. My understanding is that both fans should run on low speed whenever a/c is on. Then as required as a result of increasing coolant temperature, first one fan and then the other should switch to hi speed. By replacing the one low speed relay and the two hi speed relays (all under hood in the control box on the left inner fender) I was able to get the fans on my 90 convertible working correctly. At times one or two bars past top center on the temperature gauge is ok, at least that’s where it peaks on mine, then the hi speed on the fans brings the temperature back to normal. I don’t consider any of this as overheating, just the way it’s designed to work. But, then again, I could be totally confused🤔🤔.
karl