pitchindad

Brett great advice, I think I will do some research on how to change it and when it is time to flush and change the coolant I will fix it then.

Brett, I actually flushed the radiator and changed the coolant last December, I also changed the termostat and coolant filter at the same time. That could be the problem but I stay on top of my maintenance. I always use the Rotella coolant recommended by Cummins which I believe is SCA. I am thinking maybe I have a element in the heater going to ground when it heats up. When the thing is cool it doesn't trip the breaker but when it is warm/hot it trips right away. Just has me baffled as to what is going on. Thanks for the reply.

I know someone on here has experience with this problem so here goes: I have a 2004 Holiday Rambler Ambassador, Cummins 8.3 with 106,000 miles. I was doing some routine maintenance Sunday and discovered that the GFCI for the block heater was tripped. It kept tripping when I plugged in the heater so I assumed the easiest fix was replace the GFCI didn't help. I ran an extension cord to the cord for the block heater and it was also plugged into a GFCI in the garage and after 10 minutes it tripped the breaker. Anyone experience this and should I assume that I have a short in the block heater element or in the cord going to the heater element? I hope I have given a good description and enough information. Since I live in south Texas I really don't have to have a block heater but I am one of those people who can't stand to know I have something broke and not fix it just in case. John

I have a 2004 Holiday Rambler Ambassador and the same issue. ATC light came on intermittently, and as said above changed the fuel filter that solved the problem. Just like Mr. Wright, I carry extra fuel filters and change if necessary.