Radio fuse Which one?

[4X4SwampVan]

Hey yall, what is the difference between the radio-1 fuse and the radio-B fuse? the only thing I figured so far is the radio-B is killing my battery once a week. I unplug it and i dont have power to the radio. Very inconvienient! The fuses are labeled and in the fuse center by the drivers left foot. All stock GM. I have a stock am/fm cass radio with the cd mounted below the radio. NO mods at all. Which fuse does what?
UPDATE>>>>>UPDATE<<<<<<<
2000' 1500 5.7, A/C, PW, PDL, no alarm, working pwr antenna, 2wd cargo, 62k miles. The DC current load at the battery when the engine is off and the van is supposed to be in a deep sleep is 277mA DC. This is with all fuses plugged in and dome lights off, no cigar plugs in etc. When I unplug the radio-B fuse, the load at the battery drops to 19mA DC. The math equates the radios using 258mA DC while it is just supposed to be just keeping time. The radio-b fuse is hot all the time and radio-1 fuse is relative to the keys position, on-off. If either fuse is removed the radio wont power on. Is a radio supposed to draw 258mA while in a off postion? This van has given me perfect service for 3 years and this problem has just begun in the last 3 weeks. No changes have been made to add delete any options. All systems are in good working order. Battery is 11 months old and tested good. If I park the van for more than 3-5 days the battery will be near dead. In the past I have left this van parked for weeks and it started normally with same battery and radio. Thank you

[MT-2500]

What year and size van and what engine?
One may be key on full raido power to make the raido talk and the other may be key off power to raido memory.
WHICH FUSE HAS POWER KEY OFF AND KEY ON?

[MT-2500]

Be for you replace radio.
I would get a volt/ohm/amp meter on it and check amp draw on radio and radio-B circuit.
Post back amp draw readings.

There could be something else tied onto radio-B fuse/circuit.
Good Luck
MT

[DFBonnett]

Just to jump in quickly, this problem is common in Caddies and is often traced back to the retained accessory power (RAP) module.
FWIW
YMMV