Now the engine is back and running beautifully I’ve run into some annoying snags related to the wiring ..

The majority of the working was prepared and fitted around 7 years ago … it consisted of a number of looms with the bizarre but obligatory all white cabling … for every single device !

Slightly bucking the trend of aviation wiring I made a few of the connections colour coded .. so Red for power, Black for earth ..so, at a glance you pretty much knew what a wire was serving … then added the odd colour into the predominantly white looms. Yellow was oil pressure, Orange was oil temp, RPM was Blue….

The 3 looms were to provide a degree of separation for the primary engine monitoring instruments …. The mags … and the radio, the aim being to keep any ‘noise’ (a black art in itself) away from things like radio

Due to the very small panel space of the Ranger, I opted for a number of 2 1/4” dials, the main one being the engine monitor … serving up 2 x CHT, 2 x EGT, Oil pressure, Oil Temp and RPM as well as Hobbs.

This unit has 2 D plugs in the back …and even the instruction manual says you ‘may’ be provided with a male or female D Plug for the Thermocouples … the manual is also pretty unclear as to which way you are looking at the numbered pins … so is it Male or Female .. and is it viewed from the plug as you hold it in your hand ‘facing you’ or .. even more bizarrely … with the plug covers off .. facing away .. as if you were soldering the plug together !

Anyway, having had the engine in and out more than a few times over recent months AND taken the opportunity to rip out the old connector block .. that worked fine…just looked like the B and Q part it was ! .. I’ve got a misreading CHT and EGT a and going round and around to try to resolve the issue

Having roped in 2 sons to run through my recursive sequence and confirm I’m not going mad …. We have asked another friend to give his input …

Having reviewed and removed the question arises of WHY did I put quite so many handshake connectors in ! I loved the flexibility doing this on first fit .. being easily able to connect and disconnect things BUT … for each thermocouple and each earth and each live and each oil and pressure sensors … I have multiple ‘interrupts’ in the supply lead

Each of these points, over time, can become a bad joint … can get corrosion … suffer from my initial bad crimping (documented elsewhere .. using the wrong tool) … or just simple not like being pulled apart after years … I think st this latter part that has UPSET things the most !

Looking to simplify this setup … I’ve worked out that from PiN D plug to thermocouple end point … my ‘current’ setup has joints, as follows , PIN, a handshake at around 10” .. so 2 joints, a Ring connector at the firewall side connecter block - so 2 joints, and now, double ALL that for the positive and the negative ..so 10 connection point’s in all …. NOW plan is to reduce to 2 !

Now, extrapolate that up … 4 thermocouples … 40 connection points, reduced to 8 … will now slowly work back through the system to refresh AND reduce the connections