@Travis Thanks for all the effort. I think maybe you are right that it was an option becuase it sure looks like a factory installation. I thought that all the water cooled Mules came with an over temp warning light as standard though????
Anyhow another member directed me to a great website bulbtown.com and I was able to identify two possibilites and ordered them both.
If you are willing and your dealer can add any info I would love to have it but if not I think it's likely that I have a solution coming in the mail soon.
I fished in Canada this June with a guy from Conroe. I lived in Houston for a year in 1993.
Thanks again.