Dash Switch Bulb Replacement

[Superman]

I'm not finding this in Bentley or Pelican. Can I replace light bulbs in the dash switches without removing the fresh air box in the trunk? I'm talking about the fog light, rear window defroster, etc.

[proporsche]

No need to remove any part..the light bulb is part of the switch, on both ...

Ivan

[Superman]

Hmmm.... Thank you. I think the switches cannot be removed or replaced without accessing them in the trunk. If I can access the bulb from the passenger compartment, then I am wondering how.

Anecdotally, I faintly recall seeing switches small clear plastic (or glass) rods that reach deeply into the switch where the bulb is located. The light travels through the rod.

So yeah...I don't know where the bulb is located in these switches or how to access those bulbs.

[T6andT]

Believe depends on year, around 81’ they were accessed via front of switch by removing plastic cover. Older ones not so easy.

[Steam Driver]

What year car and which switch? On a lot of the older cars you access the bulb from the front by unscrewing the knob.

[proporsche]

take the knobs off-unscrew them

Ivan

[Superman]

The plot thickens. I have two sets of these from '78 and '83 SCs respectively. Here is a pick of the '78 knobs:



As you can see, they have a clear plastic or glass rod. One is shorter than the other. The long one will not fit into the switch from which the shorter rod was taken, perhaps because the rod broke off leaving the remainder in the switch. I dunno. Interestingly, inexplicably, I happen to have a spare rod. I suspect the rod just pulls out of the knob, but I am trying to be careful.

There are what I believe to be '83 knobs:




As you can see, these are a completely different animal. No clear glass/plastic rod.

I now suspect the way to access bulbs is to pry the little decorative disk (the one that illuminates) from the rubbery rest of the knob. Even so, I wonder how in the world electricity can get into, and also out of, it.

And I really am curious about those clear glass/plastic rods. They make me think the light must be in the back of the switch, not in the knob. Vexing. One day, I hope to discover a light in situ.

[Superman]

Bump. Does anyone know where the bulbs are located for these two different types of SC dash switches (see pics). I suspect bulbs are inside the knobs on one style, under the translucent plates which perhaps can be accessed by prying the rubber on the knob. On the other style, with the glass/plastic rods, I suspect the bulbs are in the switch itself.

[gptom]

the light from the bulb goes through the clear tube. the bulb is located in the switch

I am not sure if you can pull the bulb out from the pass side

[Superman]

I answered my question. For posterity:

Here are the backs of the two styles of SC rear window defroster switches. One from a '78 and one from an '83:




As you can see these switches are very different as are the knobs pictured above. As you can see by the glass/plastic rods attached to the knobs (in a previous post above) and by the back of the '78 switch, the light bulbs in these wonderful switches are located in the rear of the switch. This likely requires fresh air box removal in order to replace the bulbs.

The other switch, as you can see, has a smaller bulb located in the knob itself. Quite easy to replace. I will now ask, in another thread, about installing the '83 switches into the '78 car.

[Superman]

One more pic, for illustration purposes. As you can see by these pics, one style of switch has a larger bulb, like an ordinary instrument bulb, in the very back of the switch. The '83 switch uses a smaller bulb located in the knob, under the defrost icon which lights up.

[Marc718B]

Originally Posted by Superman

One more pic, for illustration purposes. As you can see by these pics, one style of switch has a larger bulb, like an ordinary instrument bulb, in the very back of the switch. The '83 switch uses a smaller bulb located in the knob, under the defrost icon which lights up.

Superman, on the 83 what type of bulb is it? Can you take a pic of it? Been trying to find replacements for mine but still can’t find one (when I purchased the car, those knobs didn’t have a bulb in them).


Sent from my iPad using Tapatalk

[Superman]

It looks like they are available here. : 900-631-132-90-OEM

This is for the OEM bulb, which is a whopping $3. Pelican also offers an "OEM" version considerably less expensive at just $1.

This bulb has no metal base. It is all glass, with two conductors sticking out at the base. It just pushes straight in.

I pulled the bulb, and it visually appears identical to this part.

[Marc718B]

Thanks a lot!!!


Sent from my iPad using Tapatalk

[spuggy]

Originally Posted by Superman

It looks like they are available here. : 900-631-132-90-OEM

This is for the OEM bulb, which is a whopping $3. Pelican also offers an "OEM" version considerably less expensive at just $1.

This bulb has no metal base. It is all glass, with two conductors sticking out at the base. It just pushes straight in.

I pulled the bulb, and it visually appears identical to this part.

Great info, thanks!

At a glance, these look to be the same as the little illumination bulbs for the heater control face plate - which can get hot enough to distort/melt the plastic stalks they mount in...

Replaced mine with LEDs years ago - think they're called "wedge" bulbs, but forget the size (T4? T5?); you can get a bag of them for a less than a buck each.

Pretty sure the switches in my '77 have the bulbs behind the little removable plastic plate, rather than the light tube design.

[Duc Hunter]

I just put them in my car. I pulled the clock, reach back there with my left hand, while using my right to twist the bezel...they came out...though I put mine in with my own wiring....so I am not sure how long yours is.

Now if only I could get those little clear stalks that go inside the knobs. They seem to be NLA.....

[Superman]

Originally Posted by Duc Hunter

Now if only I could get those little clear stalks that go inside the knobs. They seem to be NLA.....

Again, for posterity, here is a pic of the clear stalk thing. The fat part sits in the knob in the cabin, under the little defrost icon. Also, my fog light switch has a broken clear stalk. It pokes out of the knob only about an inch or so, The rest of the stalk is likely inside the switch. I may remove that switch and, if so, will look for the other half of the clear stalk. FWIW, according to my recollection, the fog light illumination works just fine, even with a broken clear stalk. I will know more later as I work on this project (which includes brake system overhaul, fan and housing cerakote, new fuel pump, etc.).

[Superman]

Referring to the picture of the switch knobs above which have the clear plastic thingie poking out....one is shorter than the other. I thought one had snapped off inside the switch. Untrue. The fog light switch is shallower than the rear window defogger. Those two different lengths....are correct.

[7783911]

Any idea what the part number is to replace that defroster bulb shown..the one that looks like a golf tee?