As I was installing my glove bax back into the dash I happened to brush up against the black thermal insulation foam that was installed on a black rubber hose behind the glove box. The black foam was crumbling and when I reached up and squeezed it, I found that there wasn't even any hose inside of it. The foam was between twon ends of a rubber hose and made it appear that the hose was one continuous hose. The hose is about 3/4" OD and 1'2" ID. When I started the car I thought that maybe it had something to do with the A/C so when I turned on the A/C it seemed that there was a slight vacuum to one end of the hose. And I mean, VERY SLIGHT. Does anyone know what this hose if for? Should I hook it up?

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FrankieZ
84 500SEL EURO 87K
85 300D 267K (and still goin' strong)

That could be the hose for the interior temperature sensor. One end is hooked up to a small aspirator motor that creates a slight vaccuum to pull interior air thru the sensor. These foam hoses crumble after all the years on them. A quick test you can do on the sensor is to cut a 3/4"x3/4" square piece of paper and place it up against the inlet grille of the interior temp. sensor with the climate control running. If the aspirator motor is functioning and the hose is intact, the paper should be sucked and held against the grille. If it doesn't stay, it's a good bet that the crumbled hose you found is the one for the temp sensor. Good luck!

Nolan

Hey Dieselguy, thanks for the quick response. I forgot to mention that this is on my '85 300D. I also didnt mention that the hose isn't just disconnected. There is about a 4-5" piece that is missing between the two ends that the foam was covering up.

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FrankieZ
84 500SEL EURO 87K
85 300D 267K (and still goin' strong)