Headlight Switch Disassemble, 1970-1971 Fury

1970FuryConv

Old Man with a Hat
Joined
Aug 8, 2014
Messages
5,739
Reaction score
5,436
Location
Richmond, VA
PXL_20220831_194148943.jpg

PXL_20220831_194219849.MP.jpg

Backside, spades B1, B2, H, R factory marks
PXL_20220831_194816657.jpg

Input Current
B1 Upper vertical spade, L1 16BK, from junction with wire from Battery feed at FB, provides headlight power
B2 Upper horizontal spade, L8 18P, power from taillamp fuse at FB, provides taillight and IC light panel power (2nd wire provided power to key on buzzer, disconnected)

Output current
H (headlight) lower horizonal spade, L2 16LG, foot dimmer > HL, and concealed HL relay (time delay relay deleted)
R (rear) lower vertical spade, L7 18BK to TL and L7A 18BK to Dimmer, which provides power for IC light panel

Resistance B1 > H: 2.3 ohms with headlight switch on, infinite with headlight switch off
Resistance B2 > R: 6.4 ohms, headlight switch in parking light position, varies from 127 ohms to 2000 ohms with headlight switch in on position. Resistance is infinite with headlight switch off.

Question: what makes the headlight switch contacts stay clean, while the taillight contacts get worn and/or dirty?

Question: is there a way to remove the black rear cover and clean the switch internals?
 
Using a tiny, thin screwdriver (like a jeweler's screwdriver) pry the four tangs to vertical and the cover will come off. Careful....a spring may come rocketing out as you wiggle it apart, so beware. After cleaning up any crud in there with lacquer thinner, the copper contacts can be cleaned and polished with the red eraser on a No. 2 pencil. Then apply a little white lithium grease to the pivot and contact surfaces. Reassemble and bend those tangs back down firmly. You probably only get one shot at the "bending before breaking" situation.

PXL_20220831_194816657.jpg
 
As the above states, as well, as the areas of the metal case that are peened in on each side of the backboard - you may have to bend those outwards too, to completely release the backboard or risk snapping it, as they're quite brittle.
 
Ross is right. Forget what I said about bending those tabs up. They hold the contacts/etc to the board. It's the two peened areas that hold the case to the board. Usually you can secure the case in a vise and "un-peen" the case using a tiny screwdriver or punch and a hammer. Or, you could grind the peens away with a Dremel to really protect the backboard from damage and use a little blob of JB Weld to bond the case to the board (and seal the hole you made in the case) when you button it back up.

Sorry for my incorrect advice the first time.
 
As the above states, as well, as the areas of the metal case that are peened in on each side of the backboard - you may have to bend those outwards too, to completely release the backboard or risk snapping it, as they're quite brittle.

Ross is right. Forget what I said about bending those tabs up. They hold the contacts/etc to the board. It's the two peened areas that hold the case to the board. Usually you can secure the case in a vise and "un-peen" the case using a tiny screwdriver or punch and a hammer. Or, you could grind the peens away with a Dremel to really protect the backboard from damage and use a little blob of JB Weld to bond the case to the board (and seal the hole you made in the case) when you button it back up.

Sorry for my incorrect advice the first time.
Thanks to you both! I'll report back after I get it apart. Will also be careful about flying spring. Will need to watch so I can see how it goes back together/where the spring installs. :thumbsup:
 
Most likely that whatever is spring loaded will have some sort of lubricant acompanying the parts that are associated with the spring.

If I had any questions I would ask @Devinism as he rebuilds these types of things.
 
Thanks to you both! I'll report back after I get it apart. Will also be careful about flying spring. Will need to watch so I can see how it goes back together/where the spring installs. :thumbsup:
I don't know for sure if there's a spring in there, but if there is you can be sure it will end up in some hidden location in your work area! :BangHead:

Pics of the guts before you take it apart can be a lifesaver.
 
Maybe I can start tomorrow evening. Otherwise, I have Labor Day weekend to give it a go (and find the f'g spring). :lol:
 
I have one of those switches if things don’t work out for you. the polished finish is in nice shape , the switch movement is great. I will test it with my multi meter if your interested. $10 and the ride. It was in a gauge cluster I had sitting on the shelf in my garage. Good luck on your switch rebuild.
109D0A66-718B-45CB-BB91-E62E048E9CC3.jpeg
AFFCC5A3-5B12-4E82-91E8-FAAA19231231.jpeg
0FA65F5E-A108-4C0D-AF1F-8C3105027D6C.jpeg
5AAFA77F-D70D-4C85-9ABA-9952990FA6A2.jpeg
2212540C-A8EF-4F10-98F0-E1D51EB34D5D.jpeg
CAC0E416-F1AB-46B4-8C9B-1A3AAF4128D6.jpeg
2CDB9816-A103-44E4-A534-A97F6841F950.jpeg
FD6C28E2-DE90-404C-BC36-2AA65388679E.jpeg
07EC1934-9E8D-4975-AD26-8BB096DDEC7D.jpeg
 
I have one of those switches if things don’t work out for you. the polished finish is in nice shape , the switch movement is great. I will test it with my multi meter if your interested. $10 and the ride. It was in a gauge cluster I had sitting on the shelf in my garage. Good luck on your switch rebuild. View attachment 555659View attachment 555660View attachment 555661View attachment 555662View attachment 555663View attachment 555664View attachment 555665View attachment 555666View attachment 555667
I'm interested. Please check the resistance and let me know. Thanks
 
Well I wired it up with my 12 volt source. It had good off, park , headlight /park together.
2FCB6E91-9632-4B8F-93B7-4BC413FB6C79.jpeg
222F1FE8-AF84-4AA1-945A-904FB974D623.jpeg
399F1179-042E-47C1-83B5-AD9748525352.jpeg
0CE4E5EB-7F94-42B0-940E-ED8BCE1C28FC.jpeg
16D5B1AE-38D7-4730-B6BE-B255C1EEDC81.jpeg
 
Back
Top