Changing gauge Bulbs

[TomoHawk]

I had two bulbs go out recently, so it's time for me to change out all the bulbs-  they seem to fail in small groups.  It sounds easy enough- you pull out the socket then push & turn the bulb to get it out.

 

But when I push the bulb in, you still can't turn it, because there are some small nibs that are supposed to keep the bayonet pins in place so the bulb doesn't accidentally come out by itself.

 

What I have been doing today is to trim the point of the nibs slightly, and sanding the solder contact pad at the tip so you can push the bulb in more to clear the nibs (the solder pad was keeping the bulb from pushing all the way in.)

 

So I would like to ask everyone if they have a nifty or sure-fire way to get the bulb out of the socket.

 

BTW-   I'm using the 4.3 watt bulbs (GE 1816), like the ones MSA sells, but you can buy them at the local AP store.  My test battery must be low, because the gauge lights up yellow with the 4W bulb, or is that correct?

Edited October 7, 2015 by TomoHawk

[Namerow]

I noticed the same problem, but I was fortunate to be able to deal with it while the dash was out of my car.  There often seemed to be a lot of 'stiction' between the bulb's locating pins (what you call nibs?) and the plastic socket.  Might be a combination of micro-dirt on the plastic and oxidization on the pins. 

 

Something I did that really seemed to ease the bulb lock/unlock action was to put a tiny bit of grease on the ramps of the plastic socket (i.e. the surfaces that the pins on the base of the bulb ride on).  I used dialectric grease because it was handy at the time.  I suppose that any grease would be ok, though, because the ramps are the strictly for mechanical engagement and don't function as electrical connection surfaces. 

 

Because you're working on this while your dash is in the car, you'd have to resort to putting a bit of grease on the end of each pin.  Not quite as effective as greasing the ramps, but it might work.  Just don't over-do it with the grease.  And use dialectric grease for sure, because some of it may get onto the electrical contact on the side of the bulb.  Try it out first on the bulb that's easiest to reach (usually the one for the clock).  If you like the result, you can do the same for all the rest.

 

I can't comment with confidence on your 'yellow bulb' problem because I'm using a different bulb mftr and wattage.  Doesn't sound right, though.

Edited October 7, 2015 by Namerow

[TomoHawk]

I also think there was also a problem with the bulbs I used before, a Sylvania #55  (7V, 3W.)  These were brighter, and you only needed about 1/2 a turn of the rheostat, but you run the risk of them burning up earlier if you turn the rheostat all the way up.  But the #55 bulb had a large globe for the glass bit, and the glass hit the socket when you inserted them into the socket, adding to the problem.  That is why I wanted to change to a real BA9s bulb, because the glass is no wider than the metal base.

 

So I'm back to the other problem of the bulb's base being too tall to fit the socket. 

 

The only real  solution I can think of would be to replace the sockets with a better one, that is made to accept a BA9 bulb without  the use of a  hammer...

Edited October 7, 2015 by TomoHawk

[Captain Obvious]

I've found the easiest way to change those little bulbs is to:

 

1) Put on a rubber glove on hand because the rubber provides better friction to the glass globe.

2) Pull back on the center wire a little to compress the spring inside the socket.

3) Once you're not fighting the spring anymore, turn the bulb with your gloved fingers.

 

Once you get the hang of it, it's really pretty easy. Don't try to push the bulb in to compress the spring and try to turn it at the same time. It's much easier to compress the spring with the other hand. Works great for insertion as well as removal.

[Captain Obvious]

And while we're on the subject... I'm no bulb expert, but I did do a little digging recently as a result of some of the stuff I'm doing to my car and here's a little bit of "Bulb Theory 101" that I picked up along the way:

The "BA9S" simply describes the BASE size and shape. It does nothing to describe the glass shape. For example:

 

"BA9S" - Means "Bayonet base which is 9mm in diameter and has a single filament."

Bulbs with a BA9S base can come in one of many different envelope shapes:

G = "Globe" - These are spherical (like a globe)
T = "Tubular" - These are usually longer than they are wide.
S = "Straight" - These are supposed to have straight sides, although they often do not...?

 

In catalogs, the envelope shape letter is followed by a number, and that number is diameter if the glass envelope measured in eighths of an inch. Yeah, I know... I didn't make up the nomenclature. So, for example, you'll see bulbs listed as "G3-1/2" or "T3-1/4". What that means is:

 

"G3-1/2" - Means "Globe (spherical) bulb with a globe diameter of 3.5 eighths in diameter or about .4375 in diameter"

"T3-1/4" - Means "Tubular shaped bulb with a globe diameter of 3.25 eighths in diameter or about .406 diameter"

I did a bunch of digging into the original bulbs (Toshiba A12V3.4) and I've come to the conclusion that they are not available on the free market. They are a BA9S base, but the glass portion measures about .310 (8mm) diameter. Using the modern nomenclature, this would be a "G2-1/2" and I've not found that size anywhere. Might be completely ubiquitous on the other side of the planet, but not here.

 

I've not checked if the larger G3-1/2 bulbs will fit through the hole in the back of the gauges, but I have confirmed that the small T3-1/4 bulbs fit fine. In other words:
 

"A bulb with a BA9S base and a T3-1/4 envelope fits in the dash gauges."

 

Sorry you started the discussion? 

[TomoHawk]

Not at all.  I usually wondered where they get those numbers, like the T-1 3/4 or T-5 for LEDs.  Your rationale for the nomenclature sounds fine, and I really would like every vendor on eBay to  read and comply!  They use BA9 or BA 15 for just about any bayonet-based automotive bulb, and the LED "bulbs" (lamps, really) should have equally accurate nomenclature.

 

OTOH-  if you went to the auto parts store and asked for a 12V,3W BA9s-G3 bulb, the only thing that will happen is the sales 'person' will ask you what kind of CAR you have- even if it (the bulb) is for your lawn mower!     

Edited October 7, 2015 by TomoHawk

[TomoHawk]

While digging around myself,   it looks like the bulbs you ought to get  are a BA9s 12V flashlight bulb, which has a pointy glass envelope.

[TomoHawk]

What do you think about this new design for the BA9 LED bulb?  Is there a name for it?

 

 

http://www.ebay.com/itm/201238059796

Edited October 12, 2015 by TomoHawk

[Captain Obvious]

I'll let you know in a week or so. A local Z buddy of mine recently ordered a bunch of those thinking they might look good. They'll be here shortly and when they get here, we'll try them out to see what they look like.

 

As for a name? No idea. That technology is moving so fast and furious right now that I don't think there are standards to describe them. Other than the BA9S base, I don't think there's anything to describe them other than "oversize" or not.
 

[TomoHawk]

To me, it resembles a BA9 tubular bulb.

 

The item name is BA9S T4W LED 2W 100lm 8-5730 SMD, which to me means:

 

BA9s "style" (9mm base, similar to the BA9s bulb, with a single terminal)

T4W = (??)

2W 100lm = 2 Watts and 100 Lumens

8-5730 SMD = 8 5730 SMD LED 'CHIPS'

 

So the T4W part was the only unknown, and a quick 'Google' didn't give any helpful information.  But if it truly has 100 Lumens, I think there may be hope for a good use.

Edited October 12, 2015 by TomoHawk