To whomever was asking ...

I checked my owners manual ('85 GL), then did an online search.  The Type 89
called out in the manual is available.  But you have to look a bit.  This
company (www.bulbs.com) calls it a "C89".  Sorry so late but I hope this
helps.  //Jack

http://www.bulbs.com/products/product_detail.asp?page=home&inventory=10185

Product Number:  C89
Ordering Code:  89
Light Output:  6 MSCP
Energy Used: 7.5 Watts
Life:  750 Avg. Hours
Volts:  13 Volts
Bulb Shape:  G-6
Beam Spread
Base:  Bayonet Single Contact
Class and Filament:  C-2R
Diameter (in):  3/4
Length (in):  1.44
Finish:  Clear