Topic

The new Ford arrived from Northumberland this morning and was rejected within a minute due to undisclosed and very obvious accident repairs. The F then failed to proceed due to a flat battery. Alternator voltage is always good, battery is a nine month old Varta so I don't know why I suddenly have only 10.4 volts unless it has failed. I shall charge it tonight, check the quiescent current and measure the charging voltage at the terminals. The car had a 400 mile run just ten days ago so I am at a loss to know why. Infuriatingly, the tell tale on the battery shows green.

It charged fully in fifteen minutes and was at 12.1 volts before charging so the problem lies elsewhere. Need to have a look at the starter connections next, I think. I need to do a load check on the battery to confirm that.

The starter motor connector can be troublesome & I’d take a squint at that initial. I can’t remember which size it is, I know I used a yellow one & all that tells you is that I have yellow faston connectors. I think it’s a 375 series or maybe 312 (3/8 or 5/16”); there was a spell when I seemed to have my hand down between the bulkhead & engine giving the terminal a tweak.
Even if this isn’t the root of your problem it’s a job to do as preventative maintenance.

These cars don’t want to be sitting about for long, the alarm system is very effective at draining batteries 🪫
Whist most of Joseph Lucas’s ( the Prince of Darkness) handiwork had be banished by MG by the time ours cars were made, the Lucas 5AS alarm system remained as the last hurrah!

A list of the Prince of Darkness’s achievements:
The self dimming head lamp………. Usually dims to total darkness at the most inappropriate times.

The intermittent windscreen wiper………. Only ever works intermittently and never when raining.

The Lucas refrigerator……. Which is why you Pomgolians drink warm beer, the bloody things never worked.

The 3 position switch……. Dim, flicker and off. The later version had, smoulder, smoke and ignite positions. Interestingly their dip switches had Low and Blow as the positions.

The Lucas anti theft device………Lucas electrics.

Lucas did not invent darkness but they did invent sudden unexpected darkness.

Lucas electrons don’t move at the speed of light, they move at the speed of dark.

And of course Lucas’s finest moment, the Short Circuit.

The Lucas motto: A gentleman should not be motoring about after dark! With the motorcar appealing to a larger market including common folk this was later amended to: Get home before dark!

Lucas. stands for: Loose, Unsoldered, Connections and Splices.

Yes, Airportable. I came to the same conclusion based on thinking it out. Electronics engineers are gravely irked by misbehaving electrons but the diagnostic works like this: Sudden but intermittent loss of volts as monitored at the cabin voltmeter. Alternator voltage within limits:13.9 to 14.5, according to load. Volts there as soon as engine is running. Fault condition knocks everything out until key is turned fully back and then everything comes back on first position.

Cable goes from sound battery to starter motor then to alternator and from there to the rest of the car so the break occurs before the starter motor and is a hard switch off not a dimming phenomenon. Break is occurring at the starter connection. that reduces the volts seen at the cabin as there is increased resistance in the cable/ starter/alternator connection.

I reckon that must be it. Off with the K and N and in through the back rather than remove the hardtop and the engine cover.

Cobber wrote:

...A list of the Prince of Darkness’s achievements:....

Haha! Brilliant!

Poor old Joe Lucas, all he wanted to do was see you home after dark & his acetylene lamps really were king of the road. The problem started when his company started playing with electricity with only a tenuous grasp of ohm’s law; base metal + oxide = high resistance, result dim bulbs or no bulbs at all.
With his acetylene lamps all you did was mix calcium carbide with water & strike a light & providing the gas jet was adjusted correctly explosions could be avoided.