06-06-2021, 06:35 PM
Last weekend we took the Fabric Saloon for a drive of about 60miles round The Borders. It is running very well and having spent a long time checking steering & suspension it is also driving very well.
However as we approached the village of Roxborough sparks started falling from under the dashboard. It had done this once before but only briefly. This time it persisted and as the ammeter was illuminated from within we stopped to investigate. Couldn't see any cause for such a display. There was evidence of some short to the wire feeding the brake lights and the ammeter was very hot.
We wrapped anything that could conceivably touch what it shouldn't in tape.
Chris sat in the back with the passenger seat tipped forward so he could get at the battery isolator if needed and I drove the 11 miles home. The battery was showing 6.4 volts so no major problem and the journey was uneventful.
On Sunday we removed the petrol tank and the SM5 switch panel, and took out the ammeter.
Dismantling the ammeter showed that the coil had melted and distorted but had reconnected itself.
During the week I made new coil using the earth core from ring main cable. The third attempt worked and it all went together. I connected a 36W bulb through the ammeter and a multimeter and both showed 6 Amps. A very pleasant surprise.
Today I simplified the wiring behind the dash. It's all quite recent and in good condition.
On reconnecting the SM5 - a very fiddly job, I made the discovery that the ammeter was upside down. Irritating and more fiddling to remove it and refit the right way up.
All back together and all electrical systems work as expected. Can't check the charging as the tank is not yet back in.
Tomorrow will be tank fitting and a final test.
Slightly worried as we couldn't see what actually caused the problem.
However as we approached the village of Roxborough sparks started falling from under the dashboard. It had done this once before but only briefly. This time it persisted and as the ammeter was illuminated from within we stopped to investigate. Couldn't see any cause for such a display. There was evidence of some short to the wire feeding the brake lights and the ammeter was very hot.
We wrapped anything that could conceivably touch what it shouldn't in tape.
Chris sat in the back with the passenger seat tipped forward so he could get at the battery isolator if needed and I drove the 11 miles home. The battery was showing 6.4 volts so no major problem and the journey was uneventful.
On Sunday we removed the petrol tank and the SM5 switch panel, and took out the ammeter.
Dismantling the ammeter showed that the coil had melted and distorted but had reconnected itself.
During the week I made new coil using the earth core from ring main cable. The third attempt worked and it all went together. I connected a 36W bulb through the ammeter and a multimeter and both showed 6 Amps. A very pleasant surprise.
Today I simplified the wiring behind the dash. It's all quite recent and in good condition.
On reconnecting the SM5 - a very fiddly job, I made the discovery that the ammeter was upside down. Irritating and more fiddling to remove it and refit the right way up.
All back together and all electrical systems work as expected. Can't check the charging as the tank is not yet back in.
Tomorrow will be tank fitting and a final test.
Slightly worried as we couldn't see what actually caused the problem.
Jim