Most 12 volt outlets are wired for no more than 10 amps. and even then the voltage drop may be considerable, For conversion from AC Watts to DC amps instead of using 12 volts, use 10.. (There are very good reasons for this, and though it is a cheat,, At anything under 100 amps it comes dang close to accurate)
So 85 watts is 8.5 amps.. The voltage drop will cause the inverter to shut down.
Solution: You could put in an HD line direct to the battery or fuse panel and a 20 amp rated 12 volt outlet Or hard wire the Inverter to the fuse panel using like 8GA or bigger wire, (Well I used 12ga but it's only a 75 watt inverter and that's on my car so it's a short run.. about six or seven feet).
