Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Turn Signal Module - Lets build a better one!

I want one too - 100%. The current auto cancel on the indicators is a joke.

Not sure about anyone else, but I would like to see self-diagnostics on every start
PS: fascinating and great work!

A joke and dangerous, so many times you're having to watch traffic and where you're going and also check the tiny indicator light to see when it cancels then put them back on.

Yes you’re right downright dangerous. Main reason for wanting a replacement!

I personally will put a toggle switch on the dash somewhere that is a SPDT Center Off for an insicator switch. It stays on until you turn it off and no guessing or hunting for the indicator lamps or computer BS. I believe my AH Sprite had that arrangement and I liked it very much.

A good idea using an SPDT centre-off toggle switch. Its common terminal could be powered via an electronic indicator flasher module and each output wired to the left and right indicators, as appropriate, in parallel with the existing wiring so that hazards still work.

Please note that the AMB/TSM2 module has 18 pins. There are 12-pin modules also, and one was sent to me for testing earlier this week - thanks Ian!

The 12-pin TSM has 2 relays, an 8-pin microprocessor ( Atmel Tiny ) and 5V regulator. The two input signals are left and right indicator stalk switches.
Momentary contact will toggle the state of the relays. Once a relay is on, a seven second time delay automatically cancels it. Even though the VSS wire goes into the module, it does not go anywhere ( Note: the pcb is marked Issue 1 ), so the automatic cancel feature is not speed dependent as with the 18-pin TSM.
Also not connected internally is pin 3 which probably goes to the Dip/Main beam relay.

Some pins are internally connected together: pins 8 &9 and 11 & 12.

Understanding the wiring diagram is not easy and there could be errors; it's a pity that there isn't a Haynes version ;-)

Pin 9 seems to feed a ground to the headlamp relay circuit, so with the TSM removed headlamps may not operate. Pin 8 is chassis ground feed into the TSM.
Pin 11 appears to go to the dip/main stalk switch. Pin 12 may be +12V power to the left/right indicator relay coils in the TSM. Doesn't make sense to me...

How it works: The flasher unit feeds 12V to pins 1 and 4 and a lamp on the inst. panel. A capacitor inside the TSM charges up to 12V from Pin 12 and feeds power to the regulator which runs the processor. A momentary contact on the left or right indicator stalk will latch on the relevant relay thus the indicator lamps will glow. The flasher unit will chop power on and off to the TSM pins 1 and 4 as it detects current flow.

This TSM does not drive headlights, only indicators.

Also this unit does not have the CMOS IC that causes all the 18-pin TSM problems.

Many thanks for your guidance on all this Alister.
I seem to have narrowed down the problem to the box velcroed to the fuse bracket.
This box is not shown on the wiring diagram but in the parts list it is No 7 EX340015
Inside it there are four micro relays.
One performs the task of changing from dip to main, though depressing the indicator stalk to do this has no effect and the car is stuck with main beam light on.
The four relays have multiple link diodes going from one to another, they must be there to stop reverse voltage flow ?
I guess if one fails this may be the problem ?
I have no means to test them ( yet)
Even disconnection of Indicator stalk, Fuel pump and ignition circuit still the main beam light is on and depression of the headlight switch turns on the fuel pump/ignition.
Good job i have other Morgans to use whilst investigations continue.
Ian

You say the VSS wire goes nowhere, so the automatic cancel is not speed dependent with the 12 pin TSM. I have one of those on my 2013 car and it certainly has a speed dependent auto cancel. If you have stopped it carries on indicating, over about 10mph it cancels after about 7 seconds. Without removing the TSM I am not sure what issue number it is.

Thinking about the TSM problems, all the M3W's I can recall with this sort of problem have not been just post 2014 cars, some have been early cars. The early cars problems that I know of have been the engine failing to stop when the ignition is cut, rather than the haunted indicators and hazard lights of the post 2014 cars. I have not been able to find Chocadoodledoo's velcroed box yet, that doesn't mean it's not there, I may just need to do some more yoga down the footwell.

I have put the 12-pin TSM back together and hot-melt glued the circuit board, so it's ready to return to Ian. I can easily retest on my loom and double-check my findings. I could have missed seeing a track from VSS to CPU of course.

Yes, a diode can cause that problem if it becomes internally short-circuit. Any dead steering diode can feed power back in the wrong direction thus producing strange effects.

Most of the diodes will simply be across the coils to stop back-EMF spikes when the coil is de-energised. They are hard to test in situ because the resistance of the coil is much lower than the forward resistance of a diode.