wendwest, welcome to iRV2.com. We are glad to have you join us here and we hope to be of any help we can offer. You should be able to access the heater core from the front hood area of the coach. As you look at the generator it will be to the upper left side. It will be in a black plastic box with many screws around the perimeter and a half shell can be remove to replace the coil. Good luck and keep us posted.
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7