I have a 2000 Silverado that has poor radio reception only when the gear shifter is removed from the park position.

The engine running does not degrade the weak signal reception. Only when the shift lever is removed from park to ANY other shifter position does the rfi occur. Place the truck back in park and reception is good again. I removed the antenna base from the fender (3 bolts) and no corrosion or rust. I made a braid ground lead and grounded the antenna base to the firewall with no results. All battery connections are clean and tight. Antenna lead is tight into rear of radio. Only when the shifter is removed from the park position does the interferrance occur?

If you put in neutral, bad reception?

How about, with ebrake applied, in neutral, turn key to off position, radio goes off(if still on because of a RAP module, open/close driver'* door....should be off)....now turn key to on, don't start....how is reception?

Does this happen on AM, FM, satellite? If you play a disc is sound ok?

update 08/27/2017

My truck has No led lighting. I performed a test by placing the truck in gear with the truck engine NOT running. I did this by placing the trunk in park, turning the key to the on position, (radio on), then opening and closing the door, then moving shifter from PARK to the other selections. No RFI occured. When I cranked the truck, the RFI returned. When I turned the key off, The RFI remained til I opened and closed the door.

The RAP Module or something being powered by it when the shifter is moved from PARK to any position. Brakes being applied has no effect.

UPDATE:
Problem solved! I started pulling fuses and checking for interference and found the daytime driving lights were the source of the problem. When I pulled the light housing and found that someone had replaced the factory 4114 bulbs with leds. I replaced the leds with 4114LL bulbs and the interference went away. Thanks for everyone'* suggestions in trying to solve this problem. KE4HIE

No, good job by you, finding the source of the interference.....and replying with the fix....

ok here is the info I have on the bulbs . No manufacture listed on bulbs. printing on base of bulbs are as follows:
05 12v 4w 3557cw
6000k n5g5.

Also here is a picture.

Osram 3557cw LED'*.