Re: '89 200 headlight fogging

[Todd Young <tyoung@wamnet.com>]

Had that problem on a car.

First check your bulb gasket, make sure the bulb is seated
in the housing correctly and the locking mechanism is
holding it in place. Otherwise, look for obvious cracks
or gaps in the housing.

Once you have found/repaired the hole/crack where the
moisture is getting in. Use a hairdryer or air hose to dry
out the housing (with the bulb out). I didn't have access
to an air hose or 120v for a hairdryer, so I made up a
funnel out of cardboard and taped it to a 12v computer
fan and pointed it into the housing and left it sit for
a couple hours.

The problem I had with the car I worked on was the locking
ring for the 9004 bulb. I had broken the old one upon replacing
the bulb and bought a generic one. Well, the generic one didn't
hold the bulb tight into its socket, thereby allowing moisture to
get in around the bulb. After modifying the generic locking
ring, everything stayed dry.

When the bulb heats up, it expands the air in the housing; if
there is a hole for the pressure to escape, then when the bulb
cools, moist outside air gets pulled in, which condenses inside
the housing. I've seen severe cases where there was a good cup
of water in the housing, in that case a hole was drilled in the
bottom of the housing to allow the water to drain, and was left
open to allow future accumlations to drain out.

Jeff Maurer wrote:

> A friend with an '89 200 asked me to post for him.  His headlight
> housings have fogged to the point that they look like DRL's.  Any
> wisdom on what he can do to fix this?
>
> thanks for your time,
> Jeff Maurer



--
Todd Young              WAM!NET Inc.
tyoung@wamnet.com       6100 West 110th Street
612-886-5051            Bloomington, MN 55438-2664
800-585-1133 ext.5051   http://www.wamnet.com/