Switch Panel Advice Needed

[John P]

Hi,

After resolving most of the issues which have kept me off the road for almost two years I am just sorting out a few remaining niggles.

Although the switch panel light switch has always been quite stiff and "clunky" after the months of idleness it has become much more noticeable and when I first operated it the lights didn't actually come on.   I measured the voltage at the headlight which was only 2.4 volts but operating the switch a number of times brought this up to 4.5 volts so I'm guessing the switch contacts are probably corroded and operating it rubbed some of this off.   This isn't a battery issue but could be wiring related.  (I do have a separate earth wire from the lamp to the body).

Interestingly the ignition switch seems fine.

I'm a little reluctant to strip the switch panel down but I suspect that's what it needs so is there any advice before I start?

Also can the contact faces be lubricated with something to help them slide and thereby reduce the force needed on the switch as I'm a bit worried I could break something using the amount of force currently needed?

John.

[Stuart Giles]

Is it an SM5 Coil or SM3 Mag switch panel. These aren't difficult to strip and clean unlike the later switches. Here's an SM5 in bits -this was in really grim condition when I got it, but will restore OK.



The 2 posts which the switch lever mechanism mount to fit through the 2 square holes you can see in the photo -the posts are retained by 2BA nuts at the rear of the panel. The domed brass wipers have been cleaned up and the contacts on the Bakelite have been cleaned too. I reassemble these with some dialectric grease on the moving parts; Vaseline would probably work just as well.

[David.H]

I too have disassembled SM5 panels, and they are not too difficult...remember nimble fingered assemblers did it for years at Great King Street!! I sprayed penetrating oil and let it soak in, and the nuts all came free without too much force - even the ammeter ones. Do the work over a large tray - bits can (and will) try to make a bid for freedom, so do it on the table over a clean floor in case you have to find a small screw! Long nose pliers are needed to remove the split pins (have new ones ready for the rebuild) and take pictures on your phone at many stages! "Oh I will remember how that went" ... Oh no you won't! Some parts will go together upside down...believe me! Then you have to take it all apart again! Just take it slowly, very rewarding.

[Stuart Joseph]

Hello. If the brass tracks are broken Tony Betts sells them very reasonably. I din't know how he does them for the price, I had to buy a similiar part for another classic car and the price was eye-watering!

Stuart