Defrost fan switch light

[pcbenz]

Can you access the light bulb for the defrost fan switch by removing the glove box? If so, is it readily accessible?  I will have the glove box out to access the clock which I am thinking of having converted to quartz movement. Also, thanks to those who assisted in the removal of my ign switch (whew!) in which I also took the time to change speedo and tach bulbs and lubricate the cables. Found the correct bulbs from Mercedes in OKC.
Does anyone have an explanation as to why the speedo runs 10 miles an hour fast with stock tires?  The car has around 160K miles.
Thanks, PCBenz

[enochbell]

PC

If you are referring to the tiny "fiber-optic" light in the blower switch then yes, it is accessed by removing the glove box and removing the switch.  You will find the bulb behind a contact lever in the switch.  If you are referring to the lights in the transluscent heater/control levers, that is an entirely different story.  Please let us know year, model, and specifics.

Best,

g

'64 230sl, fully sorted out...ooops, spoke too soon

[gugel]

quote:Originally posted by pcbenz

Does anyone have an explanation as to why the speedo runs 10 miles an hour fast with stock tires?  

You didn't give the speed, but that's a big error!  For example, if the true speed is 60mph, showing 70mph, that could be caused by a rear end swap from 3.23 to 3.75, but that seems an unlikely change.  Could the speedometer drive gear have been changed?

Chris

[pcbenz]

Yes, the defrost fan switch.  I didn't know it was "fiber-optic" but thank you for the information.  

quote:Originally posted by enochbell

PC

If you are referring to the tiny "fiber-optic" light in the blower switch then yes, it is accessed by removing the glove box and removing the switch.  You will find the bulb behind a contact lever in the switch.  If you are referring to the lights in the transluscent heater/control levers, that is an entirely different story.  Please let us know year, model, and specifics.

Best,

g

'64 230sl, fully sorted out...ooops, spoke too soon

[pcbenz]

I checked the speedo with my GPS unit and at 60 MPH true speed, the speedo says about 69 MPH.  I noticed when I took my speedo out, a plastic speedo gear was used instead of a nut to hold the back bracket securing the speedo to the dash.  Apparently, someone took the speedo out at one time previous. Maybe the gear indicates something they did. I was told by Hollywood Speedometer that they want to know the revolutions of the cable in so many feet to perhaps correct the ratio when they rebuild the speedo.  The needles sure move smooth since I lubricated the cables for tach and speedo.

Thanks for your response.  

quote:Originally posted by gugel

quote:Originally posted by pcbenz

Does anyone have an explanation as to why the speedo runs 10 miles an hour fast with stock tires?  

You didn't give the speed, but that's a big error!  For example, if the true speed is 60mph, showing 70mph, that could be caused by a rear end swap from 3.23 to 3.75, but that seems an unlikely change.  Could the speedometer drive gear have been changed?

Chris

[A Dalton]

Speedo is factory matched to differential ratio, so either may have been changed from original.
 Also, orig aspec ratio of tires was 80%, so consider that in the math.