I looked for the specs on the Legend TV also with no luck.
If the TV says 4 amps, and its 12 VDC input, then 48 Watts.
As far as the transformer stating 1.5 amps at 120 VAC (180 Watts) input, 4.58 amps at 12 VDC (55 Watts) output - welcome to the wonderful world of switching power supplies, not very efficient but small and inexpensive to make.
Thats why they recommend not keeping wall warts plugged in when not in use, they still use several to 10's of watts even when not connected to a device (thus the term "parasite" load).
Rick & Debbie; Brandy & Schnoodle Dexter & Fritz R.I.P. the Doxie "Kids"
2015 Jayco Pinnacle 36RSQS 5'er
2013 Chevy Silverado 3500HD LTZ, 6.6L Diesel Dually; B&W Goose Neck and Companion 5'er hitch