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

I redid the three soldering of the electrical plugs and put silicone sealant to stiffen the capacitor on the pcb, everything works normally, I always remain interested in the new manufacture.

Put me on the list! Thank you!

[quote=GLLOQ]After a fuel pump failure I have just looked at the flasher relay which works only when it wants, the two electrical plugs are unsoldered from the pcb, the engine vibrations with the 132 cub even managed to trigger the steering wheel control during the period of engine break-in

Thanks for the tip GLLOQ. After all the talk about malfunctioning TSM's, when my indicators failed I assumed that was the problem and with the Dealer's encouragement shelled out £x@* for a replacement, Your post got us thinking and the problem has been solved with a thirty bob relay ! (after attempting to re-solder joints) But I'll keep the TSM as a spare,

The indicator module I am rebuilding is not like the thing in those photographs. The TSM has an 18-way connector and has the flashing circuitry inside it with two relays. All the parts have arrived except the Omron relays and case. I have almost finished laying out a new circuit board and there are two tracks left to route. That task gets progressively more difficult as you have to make sure tracks do not cross each other. It should only take an hour to do the final tracks.
Then I will check everything is OK and tidy up. With a bit of luck the design should be sent off to China via Tate Circuits Ltd, and they will take about two weeks to send back the blank circuit boards. It will be about a week to get the components soldered up and then it can be tested. I only have enough parts to build one, even though some components have been bought in abundance.


I wonder if that flasher unit is for a different model? Perhaps someone could offer advice?

I think that is just the flasher relay, not the Turn Signal Module that controls everything.

I have just been browsing around TM/M3W and have spotted someone complaining about dodgy indicator timeouts. One of the suggestions made was that the battery could be either flat or past its best. His battery was 6 years old. As the battery weakens, its internal resistance increases, and so the back EMF of the starter motor will have more effect on the 12V rail. It wouldn't surprise me if an old battery can give 42V or more on a poor battery thus killing the 24V-rated chip in the TSM.

I hope to be able to apply 42V to any pin of the new TSM, but a thought has just occurred to me that the new TSM could measure the battery voltage and report the over-voltage by flashing the dashboard's Hazard indicator. Perhaps 12 very brief flashes then one half-second flash for every volt above 12? Then you could know the state of the battery.

Alister, that sounds like sorcery to me but what a good idea.

The circuit board design has seen sent off to Tate Circuits.

Alister there is a voltmeter function built into the speedo digital display.

Thanks Tim, I didn't know about that. But I imagine that it has a fairly low time-constant and would be unlikely to read peaks of 42V or so when the starter is released. The alternator should keep its output voltage to between 13.75 and 14.5V so a weak battery may not show up with a normal average-reading voltmeter. But a duff alternator would show up. My second automotive electronics project was putting a green 10-bar LED inside the instrument panel of my Austin Allegro. It displayed the voltage such that each bar was a volt over 10, so 3 bars was normal = 13V.

My TSM2 voltmeter would be a peak-detector, and be active ONLY for say 10 seconds after ignition is switched on. The highest voltage detected in that period could be due to weakening battery plus starter motor back-emf.

But if the TSM2 is immune from 42V spikes then a weak battery simply means having to get a push to start the car!