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MG Midget and Sprite Technical - Light door alarm?!

hi there,

I have a 1978 MG midget. A few owners ago, the owner did quite a few non standard things so this may be another one of those!

When you leave the lights on and open the door, an alarm goes off. Well seems the switch has broken as this now goes off constantly when switching the lights on.

I have been through manuals, dug about online and i cant find anything.

Is this a standard feature? if so, any ideas where i can get a new switch? or at least how i should fix?

many thanks
bk dyson

Idont think that was standard but I can't be sure

However the system must monitor the door opening and I suspect that it will achieve that by the switches on the inner door pillars (A Post) check both of these one on either door.
Robert (Bob) Midget Turbo

not standard, I'm afraid, but should be easy to sort out

your DPO most likely took a feed from the door courtesy light switch, and from the headlight switch, and hooked them together so that when they are both "on", there is a voltage difference that makes a buzzer sound an alarm, or that powers a relay that switches it on.

since it is not factory, the wires for it wont be taped inside of the factory wire harness, so I would think that you could follow the wires from the buzzer behind the dash (it should be making a lot of noise, which will help with finding it), and then trace the wires from it to wherever they are connected to things.

Probably one of the connections has come loose (the one from the courtesy switch, since it is sounding continuously now).


hope this is helpful,
Norm

Norm Kerr

You have complicated a very simple circuit Norm

The easiest wiring to achieve this would be to tap a feed from the lighting circuit, connected to the buzzer, this will then be wired to the door switch (this makes a contact to earth when when the door is open)
Robert (Bob) Midget Turbo

Presumably the buzzer would sound if the lights were on and the interior light was also switched on, unless there was a diode inserted in the purple/white wire from the int. light to the door switches, upstream of the buzzer connection.

Is your interior light switched on? Does the interior light actually work?
Dave O'Neill 2

This might be of interest

http://www.mgb-stuff.org.uk/lights5.htm

Regards
Shaun
Shaun

On my '78, there's a buzzer fitted, but it only sounds if you don't fasten your seat belt. At least it WOULD, if it worked... Maybe this is a US-spec thing, but there are switches on the driver's side seatbelt receptacle and under the seat cushion (weight sensor) that operate the buzzer.

I remember it going off once, years ago, and I haven't heard it since. Weird.

-:G:-
Gryf Ketcherside

This thread was discussed between 16/01/2011 and 20/01/2011

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