Combination Ignition / Lighting Switch

[VWNate1]

Fitted to roughly a Zillion British cars , this simple and effective (not to mention CHEAP to manufacture !) switch has caused *so* much anguish to LBC owners , drivers and Mechanics over the years I'm surprised there's not a book or technical pamphlet written about them .

The one in my '59 Metropolitan FHC has been iffy since I bought the car over 10 years ago , there was no detent in the various positions (you know : dim , flicker and off) once or twice it decided I didn't need headlights to drive home , always well after midnight and only when I was in a part of town you'd rather not be stranded in .

(tip : a paper clip unbent and carefully placed , will make the lights work and not let any <magic> LUCAS smoke out)

I buttoned up my brake job and front end repairs Friday last and tried to start the car to give it a test drive , no spark so I grabbed a jumper wire out of the junkyard tool bucket and off I went .

Saturday was the Metropolitan Nash Club's monthly Tech Session in Westminster so off I went with my factory shop manuals and a few tools in the boot , two nasty old Combination Switches I'd found under some rotting leaves whilst cleaning the back yard .

I took the switch out and disassembled it on a clean(ish) towel , not having any metal polish for the copper contacts I borrowed an old tooth brush and a bit of cleaner wax and soon I'd used the toothbrush and my foaming glass cleaner to de-grease the innards and contacts or 50 year old rock hard grease then I hand polished all the various contacts to a high gloss with the cleaner wax and smeared a tiny bit of white Lithium grease on both contacts and rotating / sliding parts & re-assembled it .I scavenged a spare detent ball and spring from one of the crusty old switches and all was well in Mudville for a moment .

Upon checking before re-installing it I discovered two things : one , the dim bulb engineers @ BMC made a serious design error in that the switch must needs be pulled through the dash facia before one can access any of the wires ~ this bit of foolishness means the entire bunch of wires are all jammed to-gether in a 2" hole instead of hanging down below the facia where they'd be MUCH easier (and faster) to access and re-connect , test etc. .

Two ; some long forgotten DPO / DPM had wired the switch incorrectly so I had to take the time to sort it all out and mark each wire before carefully screwing them all back into place with nothing crossed nor touching .

Imagine my surprise when I discovered the coil still wasn't getting any power ~ it turns out the main harness has an open circuit between the fusebox and the coil , it wasn't a switch failure that'd prevented it from starting .

Odd but I have a new harness I'll hopefully soon install (thanx Steve ! I've not forgotten you)

Meanwhilst I added one simple jumper wire from the fusebox to the ignition coil so it works like it's supposed to once again .

I also dismounted and de-rusted the original fusebox using diluted Phosphoric Acid and Q-Tips
so the blades in it are nice and shiny again , then I laboriously hunted up some AGX fuses as the car came to me with overly long AGC ones , yes they work but they're NOT " Just So " and
so pissed me off every time I raised the Bonnet . plus , the old fuses were rusty and made poor contact , once so poor that it burned my fingertip when I touched the fuse end .

BMC says it needs 30A fuses , I installed 25A ones and I think I'll soon modify the underdash wiring to have more fuses or perhaps circuit breakers of a proper 10A each .

I'll also install a power relay so the headlight current isn't running through the Combination Switch , this will be good when I upgrade to brighter head lamps.

All the Met guys were flabbergasted to see the dash in little bits and the Combination switch apart , I think they didn't expect me to be able to drive it home again that day .

As I was enjoying myself tinkering , I realized how simple (if overly fiddly) this routine service is and I should make up a DIY How-To replete with pictures .

Sadly I didn't have my digital camera handy , not like I'd touch it with dirty fingers anyway but a simple 'photo follow along layout would prolly help a lot of folks here .

If anyone has crusty old Morgan, TD , TF , Bugeye , Hillman etcetera Combination switches lying about , I'd like them as I want to build up a few spares from the junk parts . sadly my old crusty switches are *so* rusty , I cannot get the screws to come out .

I also need a white knob for one , Moss doesn't seem to carry them anymore .

TIA,

[Steve Simmons]

Well maybe if you didn't keep your spare switches under piles of leaves in the back yard, they wouldn't get so crusty!

Whitworth Shop restores these type of switches to brand new condition, but it sure ain't free. Nice you got them working on your own! I have only one spare, the original from my TC. There's a pre-war version in the car now which will become the spare after I restore the original one.

[VWNate1]

Yes , there is that ~ I was surprised to see them appear as I was cleaning up .

I'd thought they were safely in the boot of my '60 DHC but a whole bunch of other Met and LBC parts appeared at the same time so maybe they were dropped as the tires & wheels were going over the fence , I dunno .

I neglected to mention that IMO these switches are in fact an extremely clever design apart from having to come out forward .

Simple to service too .

Now that my Combination switch and fusebox are all cleaned up , the charge rate is more even and all the lights are much brighter , etc. etc. . this is a typical result and is why I do it to most old junkers I pick up .

I know someone here has these old switches in their ' junk box ' .