Condensation on the inside glass of 250SL fuel/temp/oil gauge

[jcochran@cox.net]

Hi,
 I am the second owner of an April 1967 250SL and ever since I've had it the inside glass of the fuel/temp/oil gauge develops condensation as the engine warms up. Does anyone know what causes this and what is the cure? The condensation always goes away and no deposits or film are left on the glass but my mechanics and I are stumped and for some reason it really bothers me.

Thanks,
Jim Cochran

[66andBlue]

There was a discussion about this problem a few months ago: http://www.sl113.org/forums/index.php?topic=17681.0
Not sure whether this will provide any help, though.
Is it ONLY the center cluster that fogs up and not the other two instruments?

[jcochran@cox.net]

Yes, only the center gauge.

Thanks,
Jim

[awolff280sl]

I've been annoyed by this fogging for years. In my case it's only the speedometer. I rigged up a little fan that sits in the shelf behind the speedo that will clear the fogging. However, ever since I went with LED lighting, I have not had the problem. But I'm not sure yet since it is dependent on the weather so I need more time to assess. But in theory, if the LEDs are not producing heat like the incandescents, and if heat + ambient humidity is the cause, then they may help lower the temperature differential across the glass and eliminate fogging.