Heat temperatures at floor vents uneven in double wide.

[alfredj1956]

The supply temperature of the floor vents on the left half of my home is 135 degrees, but the right half is 111 ? The air handler is located on the right half of my mobile home. Do I have a heat element issue ( unit has 3 elements.) , or a crossover duct issue? My unit is a Nordyne E3EB-017H handler. Just noticed the difference when it got colder outside.