Earlier in the week I posted about the strange electrical problem I was having with my five speeder. No sidelights, no headlights but sidelight/headlight warning lights lit ! but turning the headlights on activated the fuel pump/ignition. First suspect was the "Module" in the circuit but Guru Alister took it apart and declared it fit for purpose.
Anyhow, four days later and with a bad back from bending over the MOG checking wiring circuits etc I found the fault in a small plug in in the loom.
After three days of checking relays connections and multi plugs with gallons of tea drunk too I got nowhere. a concerted effort with a magnifying glass to see much closer than my aged vision allows led me to one of the two plugs on the back of the speedo. The smaller of the two plugs had a powdery growth spread between a live and an earth. This live wire was a feed to the Dash Display sidelight/headlight warning lights A test of the earth with my meter revealed a voltage track via this earth. After cleaning up and spraying with a PTFE based lubricant the fault magically disappeared. A chat with Alister confirmed it likely to be Copper Sulphate which would lead to the problems I had been having. looking more closely into why the two wires had this corrosion on them it became apparent that any water that found its way down the base of the little windscreens where they are siliconed in would drop behind the dash. Morgan have quite rightly fitted a drip tray to deflect any water away from the instruments but my tests showed it ran along then some found its way onto the speedo/rev counter plugs. Dampness causes the type of corrosion I found on the terminals. All plugs were sprayed with a PTFE/Waterproofing agent ( GT85) and an extra hood of gaffer tape over the plugs into both units. Clearly just a simple fault plays havoc and causes voltage feedback through the loom. I strongly recommend similar action for older "used" as intended in all weathers Morgans.
It is a shame that Morgan only provide a Wiring Harness Diagram and not a full Wiring Diagram with each circuit explained.
I also felt that it might be a good idea to make a cover to fit directly over the fusebox in addition to the assembly that Morgan use as a fuse cover. Doubly sure that no water can find it's way into the circuit again. Another potential problem on my 2012 was the wires from the Ignition key fouled the steering rod and each time the wheel was turned the joint fouled the main wires and evidence was there that they were being scraped away. So I put convoluted tube over the wires and cable tied them away a little, playing safe again !
Ian Parkinson
Cables covered and cable tied away.
![[Linked Image]](https://www.tm-img.com/images/2021/09/26/IMG_0624.jpg)
Main Ign wires foul steering
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Box not shown on Loom Diagram with four relays in. ( Lighting controls)
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Rear of Speedo .Plug at 3, o clock had fault.
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Rear access panel removed.
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