As a fellow oap I've copied and pasted your question into the CARS sectiong as it's not a MOBILE HOME unless you live in it.
Probably the acuating solinoid going by a problem I had with my old Modeo. Not easy job entails removing the panel for a start.
So check this section for further answers and also the CARS section where most mechinics/auto electricians would look.
Bob, November 2010