Gauges fogging up
 

Im sure this is common. Im looking through the search and cant find much. Are the VDO gauges easy to pull apart? I want to try and open one up and dry it out

To open the gauges completely, you need to pry off the front ring and remove the plastic/glass face--very delicate job but can be done if you work slowly. In most cases, you will be left with a trim ring that has slight dents from the tool you used to pry gently around the perimeter, but that will be covered by the rubber gasket used to insert the gauge in the dash.

How bad are your gauges fogged? Is there a threat of the moisture causing damage? I ask because most all of us have fogging gauges at some point, but they usually clear up after a bit of driving.

I've seen others say this is "one of things" that happen with these cars.
I've had it happen once during a humid day when I turned the A/C on.

I would agree that it's "one of those things." As others have pointed out, the best cure seems to be to take a long drive. . .;)

Borrow the wife's hair dryer, blow it on the gauge glass...takes a couple minutes and clears it up pronto.

Check your hood seals. Very often, a damaged or worn seal will let cold, moist air into the area where it hits the warm cabin air in the gauges.

Go with the hair dryer solution. Getting the gauges in and out is a pain. Additionally, it is easy to open a gauge but getting it back together without damaging the outer ring or having a scratched or damaged spot showing is difficult.

There was a factory tech bulletin on this some years back. They suggested to drill a couple 1/8 inch holes in the bottom backside of the gauge to vent it.

Your car is haunted ..................

Im thinking the car is haunted too haha. But yeah it clears up after a little bit of driving so it not really a big deal. I have heard the drilling holes idea before. My hood seal is brand new so maybe it is just one of those things. I was curious about opening them up because i would like to freshen up the faces and was thinking about doing a different lighting in them too

Air on the rear of the gages is "trunk air"(colder), cabin air is on the front of the gages (warmer). They will always fog up in colder/wetter weather. Holes in the rear helps but it's one of those things. Might want to try to to port some warm air to the rear of the gages from the heat ducts or drill some holes in the gages. The tach. is usually not affected and that's the one that counts the most.

I've had 2 911's. Both a 75 and 77. They both did it. I think I might try the vent hole idea.

Somewhere there's a post or tech article walking you thru the face removal. But like you said, if digging that deep I would change to the LED lighting.
Good Luck.

I found that cleaning the inside of the gauge glass made a significant difference in whether fogging occurred - probably by reducing the number of nucleation sites for the moisture to collect on the glass.

The tech article that talks about opening up the gauges:
Pelican Technical Article: Gauge Face Replacement

One must be careful, however, as a speedometer that shows signs of being opened might lead to the belief that the odometer has been turned back.

If you open them up yourself, they are best reassembled in a dust-free environment, or in a dust-free manner. The black gauge face shows any dust or particles.

Of course, there are shops that can r&r the gauges, North Hollywood Speedometer & Clock Company being the best, based on opinions posted here.

I agree that if you are going to open them up, lighting conversion to el wire should be considered, or at least painting the inside of the gauge housings white.

BTW, cleaning the inside of the gauge glass made a noticeable positive difference in the gauge illumination.

I really want to do something with the lighting cause mine is just horrible. Ill check out the thread and see what i want to do. Is el wire like an led wire? I also heard of a tape sort of light that some use. Anyone done this before?

There are several good posts about LED and tape lighting. Do a search when you have some time to read. Mostly I've found that just replacing 20+ YO bulbs will do a lot for better light. They dim with age.

+1 on replacing the old bulbs - that alone made a difference.

I put in the led substitutes for the bulbs and was disappointed. The lighting was a slight bit "whiter" but not brighter.

The electroluminescent wire (EL wire) appears to be by far the best way to significantly increase gauge brightness. Here is one of the key threads on that topic (complete with sourcing & installation details):

http://forums.pelicanparts.com/porsche-911-technical-forum/465857-another-alternative-getting-brighter-gauges.html

A long thread, but well worth the time to read.

I'm also getting older, and found that driving with my new eyeglasses on really helps. ;)

The other poster is right on the money!!!!!!!!!!!!!!!!!!!!
There was a factory tech bulletin on this some years back. They suggested to drill a couple 1/8 inch holes in the bottom backside of the gauge to vent it.
In my case I drilled (2) holes one at the top and one at the bottom (5/32) drill bit... very carefully...and i mean very slowly with no pressure at all. Then I took a hair drirer (set on low heat) and it cleard up in 15 - 20 seconds... never had another foged up gauge! Then I started looking for water seeping in thru the winshield and fire wall...Imagine my surprise found wet carpet under dash where the center console is... water was seeping in around the center of the winshield! Prob fixed with black RTV ruper sealant.
Ron

Another solution,
#1 Insert a medicine bottle packet of dessicant into the gauge from the back, no need to remove the glass, feasible only on gauges with two needles.
#2 requires removal of the glass but works super , paint the inside of the gauge can white. I actually turn down the brightness now.

Heat pads for gauges - Fog
 

My pet project is to try and fix the annoying gauge fogging on my 911.

I have removed all the gauges from the dash and applied insulated rubber foam to shield the gauges from the frunk air temperature. Needless to say this did not work.

I am thinking of wrapping a small ( 9 x 9 cm) flexible heat pad on each of the offending gauges.
Planning on using a 12v 10w heat pad that bikers use on the handle bars

http://forums.pelicanparts.com/uploa...1526825180.jpg

Your opinions would be appreciated

OP, if I may, you need to find out why your car is allowing moisture into your frunk.

I discovered the windscreen wiper spray nozzles were loose and allowing water to get in thru the top. Check you car I bet the sprayers are loose or the seals shot.

The other areas could be the wipers mounting area or the fresh air vent drain could be dislodged or compromised.

Last but not likely unless you drive in the rain allot is the frunk seal.

My 2 cents.

Fogging
 

I have new spray jets, and new windscreen rubbers.

This morning I noticed that the fuel, oil and rev counters looked dull after 5 minutes of warm up and got progressively worse on my morning run.

Wanted to try drilling a hole on the gauges but after seeing a youtube video on how to repair a speedo and seeing how close the circuit is to the back of the housing, I am glad I did not attempt it