Channel 40 first launched on January 5, 1967, as KLXA-TV, licensed to Fontana but operating from offices and studios at 816 North Highland Avenue in Hollywood.
In its first months, KLXA broadcast most days from 4 to 11 p.m., with English programming made up of old movies and 1950s-era reruns of network and syndicated series such as The Whirlybirds, The Phil Silvers Show and Circus Boy, ending with a Lyn Sherwood newscast from 8 to 8:15 p.m. Then, starting with an 8:15–8:30 p.m. newscast from Miguel Alonso, the remainder of the schedule would be telenovelas, variety shows and sporting events (most frequently bullfighting) in Spanish.
TBN founder Paul Crouch began purchasing time in 1973 on KBSA (channel 46, now KFTR), then licensed to Guasti.
Paul, Jan Crouch, and Jim Bakker hosted the daily religious program Praise the Lord.
The station originally had a network of low-power translators carrying the signal to other areas in Southern California; however, during 2010, these translators went dark due to declining support, which has been attributed to the digital transition, and likely universal carriage of the network by the cable and satellite providers in the region.
With the station being available on cable providers throughout Southern California, KTBN is not carried among the Los Angeles market stations available on either Dish Network or DirecTV at TBN's request; the national feed is carried in its place instead, but TBN's subchannel sister networks are not available.
KTBN's over-the-air translators K15DB in Lompoc, K21FP in Bakersfield, K26GN in Lancaster, KVVB-LP (channel 33) in Victorville, and K40ID in Palm Springs ceased operations as of 2012.