Steve is the electrical, diagnostic wizard on this site. I read every one of his posts, and I learn something each time I read one. You shouldn't have to be "adding resistance" to get normal operation. Maybe the temp sensor is out of spec when it gets warm. Why not replace it. They're not very expensive. BTW, whatever is wrong can't be too bad with MPG's like you're getting.. Wish I could do that with the 300E..
2000 Dodge Grand Caravan SE