Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 M3W battery master switch?

I am just about to leave my M3W in winter storage in France, as I go back to the UK next Tuesday, until spring. I know all the other vehicles in this storage are either on trickle chargers for the modern ones with computers/coded radios etc but all the older cars have master switches for safety. I am a firm believer in master switches but my question is about volatile memory on both the fuel injection and display. If the battery is disconnected for any period (will be around 6 months) are any FI settings going to be permanently cleared and need reloading/programming and will the readings (kilometrage) on the dash display be lost? The master switch below is the one I am proposing to fit.

You can get another version with a low amp fuse connecting the two sides with the thumb nut removed. This allows clocks etc. to continue to work but try and start it the fuse will blow so stopping a thief (or at least postponing them!).

I'd have hoped that any speedo would retain programmed settings irrespective of battery status. Quite a few cars lose any user generated setting in the ignition map, and resort to default settings in the case of battery removal, but the needed relearning process is generally not too onerous, and will be back to pretty much normal after a short drive.

For a modern five speeder, something like this best:

which when wired correctly, when operated will both stop the engine and not blow up the alternator.

The following type is ok if it is never operated on a moving engine, and is what I've fitted in a hidden location to the two speeder. But if there is any chance of operation on a running engine, you need the former.


Both pictures from Demon Tweaks, and more at:
Demon Tweaks battery isolators

yes Richard is correct there is a version I use it is called dis-car-nect about 15 pounds on the web.

Richard,

I know that but some wally is bound to try and start it to move it around, without checking if the master switch is on or off and blow the fuse. If the master is off, I am guessing they will just push it if it needs moving. I have printed a sheet with "LEAVE IN GEAR WITH HANDBRAKE OFF" in large red print to leave on the seat. The handbrake rusted on with this car in storage in the UK last year, after someone put the hand brake on.

I would prefer the sort of master switch that is on my 911 RSR, which is in the middle of the dashboard and as soon as you are in the car, you can visually check if it is on or off. You actually know if it is on, as the Brantz Trip meters, digital speedo and rally timers' LED displays are lit up. That however does not have a bypass as the DEM (Digital Engine Management) module uses a non-volatile EPROM for its programs and uses that to regenerate the injection parameters after starting. However that master switch system is about 200 times the price of the switch above. The rally timers have their own internal batteries to retain the time but not display it, with the power off.

I am not worried about theft in this location but fire safety and keeping the battery charged. If thieves get in, the M3W will be the very last car they steal. There are exceeding valuable historic Ferrari racers and similar in this location plus various modern supercars.

With the unscrewing type battery master switch, you are never going to use it to turn the engine off. That risk usually comes from overenthusiastic marshals pulling the master switch cable to turn the engine off after an incident before you can turn the car off yourself.

I had one of them set off my fire extinguisher in a Ralt RT40 F2 car on a Belgian hill climb, when I had gone into the armco after a rear suspension track control arm's titanium rose joint failed in the middle of a 130MPH bend. The car was not on fire, I was just gathering myself together to get out of the car after a fairly high G but non-injuring accident, when up he trundles and pulled what he thought was the master switch but was the cable control for the Lifeline plumbed in extinguishers. At least that was back in the days of Halon not the horrible modern sticky AFFF but about 3 litres of freezing cold Halon dumped in my lap. I didn't know I knew so many French swear words.

Last winter I had the M3W battery completely removed for about half a year. I kept the battery on trickle charger in my appartment and put it back in the M3W in april, it started on first attempt, only adjustment needed was to input the correct time, nothing noticeable to the driver was lost.
Go for your switch!

Best thing to do

I have fitted a Battery Brain with a remote control so I can switch the battery on and off without removing the cowl.

The car's been left unpowered for 4 weeks with no problems.

Also, if I recall correctly, the manual says to disconnect the battery if storing the car for a while.

Many thanks all for info