Perhaps right bulb, but wrong holder...?
Happened to me. When looking closer:
1) the metal prongs/arms were too long
2) the plastic holder had a slightly larger diameter
3) the holder had a larger distance between top and bottom prongs/arms.
Getting the correct holder should be the best alternative.
Modify? IF you decide to modify; at least with regular bulbs you won't have the LED solder joint to struggle with AND you can extract the bulb from the holder before shortening 1).
Instead of a swift test and return I left mine sitting on the shelf for a couple years... Recently when I had the dash out (another thread) I decided to try and modify the holders. No. 1) were shortened with a Dremel and tested (12V) before fitting (a few were lost as it also was the LED-solder joint). 2) meant more force mounting, but went ok. In theory 3) should result in bad contact with time due to vehicle vibrations, the top prongs/arms are not providing the intended support. In my defence(?), no. 3) was a late discovery, had I known I might have stayed away from modifying... In practice the LED holders are so far staying in place possibly due to 2). Time will tell for how long tho...
All the best,
tjr
IMHO the LED's are a great improvement for dash illumination, no retro experience lost.
Beware of +12V and Earth, unless stated otherwise and unlike regular bulbs, LED's only work one way.
