Old Man with a Hat
FCBO Gold Member
- Dec 30, 2016
- Reaction score
- Millet Alberta
Hi Theo,I'd still like to see the inside of this switch though
Ah yes, that hits the spotHi Theo,
Spare HL Switch from 1971 Cluster, 2947763
Black plastic plate on rear of switch. It contains 4 spades on the outside. On the inside, brass contacts strips used to transition power/current from input, B1 and B2, to output headlights and taillights.
The rear edge of the metal switch case is peened in above 3 tangs on the black plastic backing plate.
View attachment 555991
To remove the black plastic backing plate: 1st I tried putting the switch in the vise. This was a mistake because it has a black tab that extends outward on one side (see above). Putting it in a vise put pressure on this tab and cracked black plastic plate from the tab to the opposite side.
I tried using small punches and ball peen hammer to bend the 3 peened areas out. The indents for the peened areas were very deep. I could not get a clean hit using the punches. I also couldn’t get enough angle. I next tried small screwdrivers, but found that they slipped down and broke the tangs of the black plastic plate rather than push the peen the metal out. With 2 of the 3 tangs broken there wasn’t enough plastic to hold the black plastic backing plate in place, so I was able to pry it out with a flat blade screwdriver.
There was no crud or dirt inside the switch case, so there was no need for lacquer thinner.
Operation: on the back of the switch is a lever that moves a rectangular block vertically inside the switch case. On the side of that block that faces the rear of the switch are 2 circular indents for 2 springs. Mounted above the springs are 2 metal contacts. When the switch is moved these metal contacts move up and down with the block, making contact with the brass trips on the back of the black plastic plate when the headlight switch is in the on position or the parking light position.
View attachment 555992
View attachment 555993
Springs on switch block (yes they can be easily lost)
View attachment 555994
Contacts atop springs
View attachment 555995
brass contacts before cleaning
View attachment 556000
Peened areas of the switch case: I used curved needle nose pliers to bend these outward. The black plastic cover needs to be installed straight down into the switch case. The peened areas get in the way of that.
Brass Switch contacts on the black plastic backing plate and above the spring loaded contacts that move up and down with the block: I tried using red pencil eraser to clean the contacts. After doing so, and pressing the black plastic backing plate into position then holding it against the switch case using twist ties, I found that I still had a lot of resistance in both circuits of the switch. The switch has seen a lot of use and the spring-loaded contacts at the back of the switch block had left deep grooves in the brass contacts strips on the back of the black plastic backing plate. I used a wire wheel lightly against the spring-loaded contacts and the brass strips on the back of the black plastic plate.
View attachment 556003
brass contact before wire wheel
View attachment 556005
Resistance: after using the wire wheel, I pressed the black plastic backing plate back into the rear of the switch case and held it in position using twist ties. Taillights had resistance of .1 ohm. Headlights had resistance of .3 ohm.
Assembly: the grease at the front of the switch block was in good condition so I reused it. Springs install in switch block and then the 2 contacts above this springs using indents on the outside of the switch block to hold them in place. I used brushable Krazy glue on the edges of the black plastic backing plate. I pressed the black plastic backing plate straight down against the contacts and held it for 30 seconds. I put twist ties on it to hold it overnight. Recheck the resistances and they were still the same. (I forgot the white lithium grease on the contacts. OTOH, there was not grease on the contacts from the factory)
This is probably not the best way to fix the switches, but at a cost of $4.29 for brushable Krazy glue plus the cost of gas going to and from the hardware store, it may be the cheapest way to fix the switch. It’s also expedient if you are going to use the switch temporarily while you are waiting for another switch to come in the mail.