Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Total loss of electrics

Hi some advice please, about 10 minutes into the drive home yesterday, there was a sudden cough a backfire and the total loss of all electrical power. If I turn the ignition key I can still deactivate the immobiliser however, there is no other sign of ‘electrical life’ coming from the car with the exception of the bottom front right relay (as you look at it) which is working over time! I have checked all the fuses which are all good, it a new (6 months ago) battery and the Regulator Rectifier has been upgraded by M3S services about 5 weeks ago.

Not a massive fan of the dark art of car electrics, can I ask has anyone experienced the same or something similar and is the solution as simple as changing the relay?

Despite the work done, it may be the battery/charging system. If the voltage during a run drops below a certain point everything shuts down. You may have had a charge when leaving but running with lights on, as I do, will run it down fast if the system is not charging.

Added because...

This happened years ago and the stock rectifier had died for no apparent reason. The people at the bike shop confided to me that it was delicate also known as a POS. After not a long time running the voltage drop hit the ECU and everything stopped. I replaced the rectifier with an H-D model. Made in China but fairly bulletproof and have never had that problem since.

Agreed. The day I brought mine home in 2016, after about 45 min, all power suddenly faded. After lots of discovery by the mechanic at the dealer, he found that the grounding wire in front/below the oil reservoir was not making good contact. There was plastic from the factory preventing full contact. But of course this was a new vehicle. Woudn’t make sense that yours would have this issue if not fairly new. But something where the battery is not getting recharged.

Which make of battery did you fit? There have been problems with the Exide battery in the Alternative parts list failing soon after installation.

Have you tried jump leads?

Happened to me on the way back from IoM1 in '22. Phil B swapped the rectifier out for me and no problem since (with the charging circuit - also moved to a Lithium-based battery around the same time).

Evening all, thanks for all the advice, just a quick update, it is an Exide battery that I fitted however not sure it’s a battery issue yet!!, I am getting a voltage ( 8 and a bit volts) between the positive on the battery and the chassis so I guess I’m looking at a short? Too bloody hot at the moment to go chasing wires, day off on Thursday, hopefully it will have cooled down a bit by then.

That sounds like a dead battery, as Chris said there have been numerous Exide battery failures.

The car is negative earth so you should be getting 12 and a bit volts.

Pretty definitely a dead battery and likely partially short circuited internally so even jump leads might not help.

I'd recommend you go to Halfords and get a Yuasa U1R which fits straight in and works fine - it's what I use.

https://www.halfords.com/motoring/motorcycling/motorcycle-batteries/yuasa-u1r-garden-battery-105605.html?_gl=1*wrbkc5*_up*MQ..*_ga*MTQ5NzQ0MDgzLjE3NTEzNzU5MDY.*_ga_VK44BRER97*czE3NTEzNzU5MDUkbzEkZzAkdDE3NTEzNzYwMzUkajYwJGwwJGgw

I removed the Exide AGM 12-31 battery from the Alternative Parts List several years ago after many failures were reported. The last entry in the list of suitable batteries actually states not to use the Exide battery.

The Yuasa U1R does seem to work well and at a reasonable cost, a good buy.

Afternoon all, as advised, a trip to Halfords for a U1R battery has resolved the problem thanks again for the help