Battery cut off switch

[Remyd]

Fitted a battery cut off switch and new battery to the mg today. Pretty straight forward and easy job even for a newbie like me. Planned the work in my head well in advance and it was plain sailing.

[Dave Wheatley]

Well done. I've had trouble for a few months now with battery going flat after a few days standing. I would want my cut off switch to be more accessible though. Blooming daft place to site a battery when there is plenty of room under the bonnet!
Isuspect my flat battery problem could be my cheap and nasty radio with the memory live wire.

[Ian F]

Dave, my cutoff switch on my BGT is on the bulkhead just behind the passenger seat. Easy to reach from the driving seat. It interrupts the negative earth cable so is very easy to fit.

Ian F

[Tom Brearley]

A really good mod for working in the electrical system, and also handy as an immobiliser if the switch is the removable 'key' type. You just need to be aware if you have passengers in the rear, or any bags stowed behind the seats, that the switch might accidentally get knocked, killing the ignition! Guess how I know...

[Ian F]

Also kills the alternator if the engine is running when the battery is disconnected!!

Ian F

[Dave Wheatley]

Thanks Ian and Tom.
I think fitting the key type switch should solve the accidental switch off problem.
Ian how did you route the negative cable to your cutoff switch? On my car, single 12v type, the negative terminal is towards the rear of the battery "box".

[B Faiers]

Just a quick warning.... If the switch is the red removable 'T' shape key type.

Be aware that the plastic key is not hard wearing and after some time the end will wear/compress and not have enough length to push the contacts in the switch together. I cured the problem with a self tapping screw in the end of the key, but not something you want to be doing on a cold dark night. The other altenative is a muti-jointed passenger who can reach behind the seats to push and hold the key in place whilst you drive

My final solution was to buy a better quality switch with a non-removable key. As the twist switch is black it hardly shows against the black carpet so is not obvious to the casual observer.

[Ian F]

Dave, this is what I did:

1. Remove original cable from battery to earth
2. Buy new cable with two ring ends. Make sure it is long enough to reach from original earth point to battery switch.
3. Assuming the battery switch has two posts with nuts, as I believe they all are, attach original earth cable from battery negative to switch post (it will probably require a different orientation).
4. Attach new cable from original earth to switch.
5. Hole in the rear bulkhead requires to be in location giving space for switch body in battery box, behind passenger seat. Key sits conveniently to hand behind seat.

I have the two 6 volt batteries, so you may need longer cables?

Ian F

[Ian F]

Just a quick warning.... If the switch is the red removable 'T' shape key type.

Be aware that the plastic key is not hard wearing and after some time the end will wear/compress and not have enough length to push the contacts in the switch together. I cured the problem with a self tapping screw in the end of the key, but not something you want to be doing on a cold dark night. The other altenative is a muti-jointed passenger who can reach behind the seats to push and hold the key in place whilst you drive

My final solution was to buy a better quality switch with a non-removable key. As the twist switch is black it hardly shows against the black carpet so is not obvious to the casual observer.

I have these red keys in my BGT and Midget (and in other cars I've owned). Never noticed any wear at all and I disconnect whenever parked.

Ian F

[Dave Wheatley]

Ta for the tip B Faiers!

Thanks Ian, it was how you got the cable through the bulkhead that I was wondering. Thought there might have been an existing hole!

While we are on about batteries, does anybody else have trouble undoing the lid "screws"? As I undo say the third screw, I find that at least 1 screw that I have undone has done itself up again. Very exasperating, and the last one has always seized up anyway. I am tempted to cut the screws off, and install large self tappers.
Edit. Is there a name for the lid screws? Polite answers only please!