Speedo Innards Questions

My guages were burned out and speedo dangling so I found a NOS and installed it. All works, but as I was clearing the work bench of the old unit, I decided to look inside just out of curiosity to see what failed. In the temp unit, the very tiny wire inside had broke. I'm assuming that's the common issue. First if all, the break is in a place away from the wrapped area so can that be soldered back to connection (assuming my soldering skills could accomplish it)? Or will that create resistance issues? Second, in the pic below, is the colored lense for the idiot lights part of the guage and some sort of tape that I'm guessing held it on. When you put these blobs up to a flash light, you can tell they are a red color which is of course is the color for the oil and ammeter idiot lights. The light for the headlights did not fall apart as these others did. So does anyone know what these blobs actually were? Any replacement suggestions besides a piece of red plastic? Anyone else ever mess with these? Just thought I might try to repair it as a spare.

 

Tape to hold the jewels in place. The jewels over the indicator openings.

I've use pieces of a red plastic file folder as a replacement.Not transparent, but the light comes through sufficiently. The jewels are transparent, but really dark, so you need something that blocks quite a lot of the light.

Make sure you've got the right bulbs in the sockets. There are different types of bulbs with the same base that have different candlepower. Higher candlepower means more watts and more heat. Pretty sure you want a GE 1816 at 4W.

 

FSM says #51 for six-volt, #53 for twelve volt in the various indicators.

Except "instrument" lamp = #55, or #57 respectively.

Or whatever those cross-list to today.

 

So how to get replacement jewels?

 

The GE #53 is a 2 watt bulb which is what you need for alt or gen/oil. As Tim shows (1816) is a 4 watt but these lights don't stay on very long so they don't have enough time to generate a lot of heat. Clear tape is used to hold on the colored plastic jewel.

A pencil soldering iron will work to repair your broken wire. Use solder for electronic circuits and not lead acid.

 

I'm wondering if a little epoxy on the edges to hold the jewel would work better than tape considering the heat issue. Interesting that the high beam, which I would assume would have been on longer, thus more heat, did not fall off.

 

After 60 years, the adhesive on the tape dries out. I think you could, in good conscience, use clear tape and expect it to last for at least half that long. I would try clear ShoeGoo if I were to use an adhesive, but epoxy would likely be ok too.

Re replacing the jewels, you could try the wrecking yard.

 

the jewels in mine looked like colored tissue paper.kids lego sets have some transparent blocks in different colors,chop one up

 

Mine looked like those colored plastic report covers the kids use for science fair papers. Almost like a thick plastic sheet. And as Tim said, it was just taped over the back of the indicator.

Or are you talking about the dome shaped things that fit in the little tubes?


As long as you still have the tubes, could you use a colored LED or bulb?

Never mind, you are talking about the little plastic dealies behind the idiot lights. Ya, mine were as described above.