In 1993 I bought a new/really leftover 1989 Honda XL600V and within the 1st 5k miles, the bulb behind the temperature gauge blew.
I rode to Walmart & got the closest match and taped the extra bulb to the inside of my toolbox lid. It never failed again.
After an accident in 1995, it was 1997 before I located a replacement XL600V with just 2,700 miles.
Sure enough, in a couple of thousand miles, that bike's temp. gauge light blew.
I remembered the spare bulb and it was still there in my toolbox! LOL