According to Laurens last post above he has thoroughly checked out speed sensor and associated wiring and connectors. Note he reports the speedo works correctly and TSM cancels the indicators when moving. The ECU is obviously receiving something as well since the idle problem dissapears when he disconnects the speed sensor. This of course interrupts the speedo reading, hence my suggestion of just disconnecting the ECU speed feed as a temporary measure where there is a three way split at a bombtail.
BTW please note this present discussion relates to pre-2014 M3W's. Among others there are many differences to the TSM on the later models most notable being the integral indicator relay and a different connector with more pinouts. Main loom is obviously different to accommodate, plus of course cooling fan, heated seats and likely many more minor changes.
I agree, from what Laurens says the speed sensor, TSM and ECU appear to be working although not as they should which possibly indicates an erratic signal input throwing off the components. Having experienced over 44 years of Morgan erratics especially electrical I can't remember how many times it came down to poor connectors, bad earths, shorts or an invisible break in a cable that produced intermittent connectivity. Most recently my temperature gauge on the +8 started reading hotter than normal then back to normal temps and was always reading about 10 degrees above actual temps, the thermostat connector seemed a bit loose so cleaned and tightened it up now consistently reading 5 degrees cooler; but of course I bow to better judgement.
Bruce 1964 4/4 Series V Comp (Megan) 1994 +8 (Maurice) tis no more 2013 M3W (Olga)
