Of Per Lindgren wrote:
"I believe it's a LED, not a bulb. I am not 100% sure though. Just FYI."

I think Lindgren's right.  My '83 Vanagon has a green one and a friend's '87 Jetta has a blue one.  Blue is one of the hardest and
most expensive LED's to make.  I beleive mass production on Blue ones didn't start until mid '80s.

Also, I've seen many an LED become dim with age or excess current.  I'll bet the LED is bad.

Any color LED should work as a replacement in the circuit.  I don't know what kind of base the stock one is molded to, however.  I'd
try bringing the old one into Radio Shack before going to a dealer.

Andy Ellis
'83 Vanagon