Hi I have a 98 quad 4 ld9, and my electrical is all messed up. When my car is cold it works A1 bananas but as soon as it gets warm/hot my cooling fan stops working and it idles really low (barely keaping it alive) around 500/550 rpms. While its hot when i unplug the ECT sensor, everything goes back to normal. The idle jumps back to 900 rpms and the coolong fan turns on. I checked over my wires and none of them a corroded or broken. I unfortunatly can't take it in the shop to get it scanned because this is my first car and I am getting it ready for me to drive before April
just a thought..have you tried changing the temp sensor??