There are quite a few variations of the switches made by Arrow used by Lotus at the time on their cars. Not sure anyone would go for buying 6000 of each
However in 45 years working on these car electrics and owning 17 Lotus' I can honestly say I have never had to actually change the whole switch.
I do have quite a few in my stock that car owners purchased and gave me as they were unused and other times I have just removed the trip over contacts where a component fault burnt the contacts.
The replacement switches are real shiny plastic finger pushes and sharp edges and not quite as nice as the originals especially if just changing the odd one.
The switches are really easy to pull apart and clean even for me with big hands and roughed knuckles. The hardest part is getting them unscrewed out of the facia in the beginning
Main thing is the switches usually fail because the contacts have just got dirty and a simple clean up is all that is needed.
Once out of the facia/dash on a clean work surface gently just prise the four retaining tabs up enough to clear the rear body.
- Switch retaining lugs
- Prise four lugs away
The switch must then gently be parted and MUST be done with the rear lucar contacts facing down. I will explain why later***. The switch finger push can then be lifted out and should retain the springs and pins but don't worry if they do drop out.
- orientation when parting
Keeping the Lucar contacts part still facing down observe the orientation inside of the metal switch over contacts.(*** had you opened the switch the wrong way these would have dropped out and left you scratching your head which way they went. These can be flipped end to end and as such fitted opposite ways or the same way depending on the intended function of the switch. Also note which side is which way round relative to the rear Lucar connection so the original wiring remains the same. If the contact arms can't be removed or just one even welded together at the contacts then the base of the switch is no good. You may want to still use your finger push part to keep the old plastic looking the same on all switches though. (personal choice)
- beware which way round the arms
If free then remove the metal strips and turn over to reveal the contacts on the arms and at the base of the inside of the switch.
- Remove arms & clean ALL contacts
With a small needle file or nail fail clean all the contacts and with some 'spirits' Gin or Whiskey/Whisky will do
I use 'panel wipe' or a good electrical cleaner clean the base and contacts thoroughly. Place the contacts back in the correct orientation.
With the finger switch part now these are just pins and springs which sometimes get sticky as the lubricant has age dried out. Just push up and down the pins to ensure they are free or better still take them out thoroughly clean if any Gin left. I then just use Vaseline or a quality electrical grease just to lubricate the pin shafts and a little on the tips where they ride over the contact arms. Be sparing though you do not want it to get grease all over the contacts. Some like to use some dialectic grease that is OK but keep WD40 well away.
The Vaseline also help reassemby now as it will retain the springs and pins into the finger trigger part which should be dropped into the contact body of the switch from above so the contact arms do not come off the side retaining spigots.
- Clean pins & replace
Press the two parts together then bend the four retaining arms back down.
The switch should now be fine
From what I recall the switches 20 years ago were around ?15 so not sure what they would cost now.
This may not be much help if switches already purchased but hopefully useful if anyone has an 'iffy' switch and is well worth trying before spending out unnecessarily.
All the best
Steve
PS....apologies for dirty grubby fingers I have been doing a few big horrible dirty jobs lately which included rubbing all the laquer off my alloy wheels. My wife says I do scrub up well though