Can anyone tell me what the switch on the back of the indicator switch was for, as seen on this early LT Museum shot?

http://www.ltmcollection.org/photos/photo/photo.html?_IXMAXHITS_=1&_IXSR_=6mZz5C6zan0&IXsummary=themes/theme_sub&IXtoptheme=Buses&IXrefine=RM-type&_IXFIRST_=97&IXenlarge=9889821

Thanks

Rob

My bus number (if any): RM13

Rob,

Have you posted the right image? You can't actually see the indicator switch in this view, it's up on the left above the driver by the starter & light switches. (Just waffling because I don't know what the switch is at the back of the trafficator!) I think the big blob is a CAV badge but not sure about what looks like a toggle switch. Regards, Danny.

Hi Rob
I think the photo is decieving. I think that what purports to be, or is described as, " a very old photo" actually is not as old as it may be described or believed as. There is significant wear to the chequer plate to the right of the drivers seat, the accelerator pedal appears to be quite worn and the jubilee clips to the cab heater hoses appear to be shiney replacements. So, probably not a photo from the sixties showing new condition. More likely to be late seventies perhaps, bearing in mind the floor wear? So, what could the switch be? Bearing in mind its location, my guess is a garage bodge to fit the then called "four way flashers"- hazard lights.

My bus number (if any): RM531

The image I am looking at is 1998/70415 taken on 25 May 1959.
The picture is probably of RM 9 as it was taken the same day as the side one. Its certainly not a 70s picture as the mods putting the timetable holder on the "dash" and the plate to reinforce the fixing of the heater cord hook by the cab light shown in another image on the same date have not been done and these were done at first overhaul in 1963.

There is another cab photo on the site of a different bus,(no steering wheel centre) 1998/72753 this clearly shows the switch and that also has a toggle switch This is the one taken on 12 May 1959 and is probably of RM 7.

I have never seen that switch on any indicator switch before. It must have been a feature of the very early RMs only. At that time indicators on buses were very new and were being retro-fitted to all LTs motor buses, but the ones on the RTs etc didn't have this feature so it must have been exclusive to the RMs. I cannot even think what it would have been used for except perhaps to extend the signal time as the early ones had a self cancelling feature that was quite annoying to drivers.

My bus number (if any): RTL 960, RMC 1458 RM 1585 and 15 RTs

Hi Rob

I have one of these switches which is not the usual type of LT CAV style, and is not fitted with the additional small switch.

There is almost no room in the diagphram housing for a switch and it's wiring so I have no idea of why it's there but would be very interested to know what its for, never having seen one before.

Claire

My bus number (if any): 2330 etc.

Whoops OK, didn't look at the photo details link. Perhaps the perceived wear to the floor is a flaw to the photo?
Got to agree with Claire though, having dismantled my CAV LT indicator switch, its pretty busy inside with not much spare space for wiring. The override to keep the indicator "on" when stationary to prevent the self cancel is interesting.

My bus number (if any): RM531

Still seems a bit of a mystery. I recieved this email, which may help.
'Right. Hope I can explain the trafficator switch as explained by a CAV trained electrician
There were four types of the CAV trafficator switch like as fitted to the RMs
The manual centring type that we all know well that were fitted to RM pre refurbishment.
The diaphragm type that would self centre after a short period of approx 5-6 flashes, which is similar to the one above but has a crude type of restrictor valve under the cover at the rear of the unit, that lets air in to the body to return the switch to centre. These are often found on RT/RF vehicles.
There is a mechanical self centring unit which has a more square back end to the casing.
Lastly there is an electrical self centring type that is also squarer at the rear and has a screw on the top plate behind the trafficator switch itself, which can be adjusted to increase or decrease the time for the self centring to be activated via the resistor.

He believes that there were never any switches behind the trafficator switch as it may interfere with the operation of the trafficator itself by the driver and would doubt if the ministry would allow it anyway'.

I have posted an up to date photo of RM13, I had a break from the rebuild of over a year, now I'm back on it. I need to completely rewire the bus, any advise would be welcome.

Thanks

Rob

http://rob-duker.fotopic.net/p62410632.html

My bus number (if any): RM13

Not sure that helps at all Rob! Your man is denying what is clearly there and that is a toggle switch on the back of the unit. It would not hamper the operation of the unit as the angled fitment of these is different to that of the RTs and RFs. All the self centering ones were deactivated on the RT family after a short while, its not easy to do with the vacuum ones, Claire Green told me how to do it.

There is another type which was quite common on provincial buses and to ook at is almost identical to the RM/RT ones, that is the one with a plastic see through handle with a flashing bulb unit under it. A metal handle over that would render it almost identical to the RT ones until you take the top off and find the wiring and operation is totally different.

My bus number (if any): RTL 960, RMC 1458 RM 1585 and 15 RTs

The same photo is on page 46 of Ken Blackers volume 1, it is a little clearer in the book.

My bus number (if any): RM531

Lokking at the LTM site you can buy images, can they not do a high res scan of a small part of the photo for you or can the master (electonic i guess) not be manipulated to give greater deatail as it looks th have writing either side of the toggle switch

Mark

My bus number (if any): RM1414 sort of