I have a 1999 American Eagle with a model 81-0271-12 2000 watt Heart Interface Source Manager.  When boon docking, and operating on the inverter, I am getting power use spikes about every 20 minutes which peg the DC amps at 130 and the inverter makes a strained electrical noise which sounds similar to a noisy transformer.  This lasts for about 30 seconds and the system goes back to normal.  I tried unplugging everything running on the 110 system but this did not help.  Any thoughts before I spend a fortune at the shop?