Ammeter and 4 Position Switch

[Ron L]

Had some fun today on the bench. Took apart my '48's (Tilly) ammeter and 4 position switch yesterday. Love how this old stuff was put together so simple. Haven't had lights for 5 years. Before buying a new switch, decided to brake down and do something. Took switch apart, cleaned it up real good, and greased with "dielectric grease". Did the same thing to ammeter (without the grease).



Now I have Low & High charge readings AND Dim & Bright lights. Its amazing how this old stuff (56 years) still works

[Ron L]

HEY. Where's my picture???

[Bigdog]

I fixed it.

[Ron L]

Thanks BD

[Rudi]

Hey Ron:

For those of us who are Electrically Challenged or is it Little Parts with Glass and Wires Challenged , would it be possible for you to walk us through how to take one apart without destroying it and how to clean it up and reassemble so it actually works again

Both of mine need some TLC

[Ron L]

OK Rudi. I'll do the easy one first so as not to be too long winded...

The 4-position switch is disassembled by removing the 3 screws from the back. Be careful when taking apart as there is a spring inside to keep pressure on the round connection plate. Once apart, it is very simple to figure out. Just clean all contact areas with a very fine grit paper & wipe clean with alcohol. Coat all contact areas with dielectric (tune-up grease). This prevents the brass from corroding quickly and spark burning. Assembly is simple as there are key slots so things go together in proper alignment.

I didn't take any pics disassembled. Wasn't thinking at the time. However, this is not real difficult IF your careful.

The above switch works perfectly - believe it or not

[Donny M]

Ron,
Nice write up

One thing:
I would use a grease such as LUBRIPLATE "AERO" or some other lithium grease. Dielectric grease is non-conductive and should not be used on a switch.

[Rudi]

Ron:

Already saved as an html. Will continue to add as you post. once complete will send to you for your approval. Many thanks. Very well done!

[Ron L]

Dielectric grease is non-conductive and should not be used on a switch.

Donny. Didn't know that. I figured it was used for points, spark plug boots and such, it wouldn't interfere with current flow. Thanks.

Rudi. Take note to what Donny mentioned. I'll take a shot at the ammeter next............

[Bigdog]

Actually, dielectric grease is quite appropriate for this application. It is a barrier against oxidation and electrical contact is created as the switch wiper passes across the fixed contact wiping the grease away for contact.

[Donny M]

Ron L wrote:

I figured it was used for points, spark plug boots and wouldn't interfere with current flow.

You are correct it's used for points on the rub block not the contacts. And the plug boots to keep moisture out.

Nice job

[Ron L]

The ammeter is more difficult to disassemble & assemble due to the face cover. I would not recommend disassembling unless gauge is not working. Be sure to check that "grounding" is not the problem, first.

2 nuts through a bracket are holding the ammeter behind the dash panel. Once removed, start disassembly by gingerly prying face holding cover off. I used a screwdriver & needlenose pliers, rotating in a vise with wooden pads in the jaws (Watch the glass face!). Try to do as little damage as possible, for the re-assembly. Next, take the 2 nuts off back. Carefully remove gauge face & needle assembly (Needle is the most sensitive part. Be careful). As you can see by the disassembled ammeter pic in the first post, there's not much to this gauge. My ammeter had lots of rust dust loaded in the magnet on the needle assembly preventing it from working properly. I cleaned the inside real good. Removed all the rust from the body cavity and spray can painted it. Also, the two bolts were loose, so I removed them from the needle assembly, lightly hit the holes with a ball peen to make them smaller, and pressed the cleaned up bolts back in (The bolts are knurled up by the shoulder for press fitting). Cleaned everything up with alcohol (or whatever you choose - nothing oily or greasy) and re-assembled. The rubber gasket under the glass face was no good, so I used permatex "form-a-gasket" in its place. After everything was put together, I placed the gauge back in the vise to peen the flange back. I used a tiny hammer and flat faced punch, rotating as I went. Again, be careful of the glass face. It looks real good. As far as how long it will last? No guarentees, but the price was right!

[Rudi]

Ron:

Excellent!

It has now been copied and pasted into the original. Will need to organize a bit, but that will be the easy part.

As for the previous questions posed and answered by Donny, BD and of course yourself, can I get a concensus and an updated wording to reflect which grease goes where - pics would be nice.... for those of use who are still challenged.....

Do you have pics of the re-assembly?

Excellent stuff though, and I really appreciate it Ron.

Now, we need a restore article on the head and tail lights - with pics too....

[Donny M]

Bigdog wrote:

Actually, dielectric grease is quite appropriate for this application. It is a barrier against oxidation and electrical contact is created as the switch wiper passes across the fixed contact wiping the grease away for contact.

I humbly disagree.

Webster defines a dielectric as follows:

dielectric: so called because it permits the passage of the lines of force of an electrostatic field but does not conduct the current. A material, as rubber, glass, etc., or a medium, as a vaccum, gas, etc., that does not conduct electricity but can sustain an electric field: dielectrics, are used in capacitors, between adjacent wires in a cable, etc.


An electrostatic field such as RF. The wiper in a switch will not completely remove the grease.
IMHO there are more suitable choices other than a dielectric grease.

Oh, and remember cake are square, pie are round

[Bigdog]

Donny, dielectric grease is used in applications such as automotive light sockets, connectors etc. where shielding against moisture is essential. In low tech applications like this, the physical contact such as the switch wiper contact are sufficient to allow sufficient current flow for normal operation.

Your turn!