Friday, 21 October 2016

Tacho photos

Halfie suggested that my comments about Erin Mae's new tachometer would benefit from a photo or two. Since I'm sure that, even so, they're not every reader's cup of tea, I've taken the photos against a different background. If you get to the end of this post, you can see whether your guess as to what it is matches the final revelation!

The back of the new tacho has two sockets. The one with 8 terminals carries most of the connections. The one with 14 terminals uses only three for this application – two to connect to button switches used in setting it up, and one for an output for a warning buzzer, should the engine exceed a user-defined maximum speed. That's not going to happen, so Ive asked technical support if I can just remove the 14-terminal connector once configuration is complete.

The top two bundles are the 8- and 14-pin connectors with their wires. The one at the bottom is the adaptor for connecting the 8-pin socket to the existing wiring harness. Erin Mae's current tacho has a large whitish connector on the back and I'm meant to be able to disconnect it and plug it into the adaptor's white socket. That's where things get interesting. Here's the diagram from the engine manual showing the existing connections.

If I position the new adaptor to align its green signal wire with position 4 on the diagram (where the alternator lead is to be attached), it looks like this:

However, that leaves some of the remaining wires apparently not connected to anything, which won't be right. But it's a bit complicated by which way round you're looking at things – back or front of the plug, etc. So that's the substance of my main question to technical support, who hopefully will be back from holiday on Monday. If need be, it looks as though I could re-arrange the positions of some of the terminals in the adaptor plug. But I can't do anything until (a) we get a response from the, hopefully, helpful techie, and (b) get back up to Erin Mae to look at it all in situ.

Now for the background revelation:

It's a table cloth made from PVC-ish material from John Lewis. Some of the map elements are in English and some in German or Dutch. It's quite good fun to plan impossible routes as you eat your lasagne. I've invented a game in which you have to pick two towns / cities with the same initial letter and the greatest ratio between the real distance between them and the distance on the map. So far I haven't found anything to beat Rio and Reykjavík.


  1. The "final revelation", Martin, or the "final revolution"?

    1. Of the alternator or engine, I sincerely hope not. Of the world, I suspect not yet. Of the existing social order, following Brexit, who knows!