Alarm remote control broken

[Clipped]

anyone know what usually goes wrong with an alarms remote?

when i press the button the light stays on, but only half as bright. it doesnt arm or disarm the car either.

so now i have to jump in, turn the key to start position, and press the valet button.

this sucks.

[Original Burnedfingers]

Did you try a new battery?

[Clipped]

i wouldnt think it was the battery since the light stays on... but no i havent tried.... i did try taking the battery out of the other remote, which is also broken... and still nothing.

i changed the push switch and still nothing.

[Original Burnedfingers]

when i press the button the light stays on, but only half as bright.

Had a similar thing happen to the Wifes Envoy. Try the battery first before ever changing ANY parts.

Is this an aftermarket alarm that was added to the vehicle?

[Clipped]

yep, its an aftermarket alarm...going to look for a battery tomorrow...its one of those smaller than AAA 12 volt batts.

[Bobken]

Hi,

Seing your details earlier, I hesitated to ask if you had replaced the battery, as this is the obvious first move here like burnedfingers has said, and should be done before trying anything else.

I am guessing that this is probably all that will be wrong here, as there will still normally be adequate current to dimly light an LED, long after the higher current most-likely needed to adequately power a key-fob radio transmitter. Also, with use the battery voltage drops, which, down to quite a low level will not necessarily affect the LED operation, but will fall too low for the transmitter electronics to function.

Don't forget that the radio signals need to be powerful enough to penetrate a metal enclosure (in most cars) as the receiver sensor is probably hidden under the dashboard or the bonnet (hood) of the vehicle. This is not exactly ideal, anyway, and will have some shielding effect which reduces the effective signal-strength.

I hope that a new battery solves this issue, and I would give this more than a 50:50 chance.
Incidentally, it sounds from your description that your battery might be an MN21 (28.5mm long x 10.3mm Dia.) assuming it is 12V as you suggest.

Regards,

[Clipped]

ok, put in a new battery and it worked....

the switch i replaced was stuck down and therefore drained the battery.

i tried the battery in the old remote and it didnt work, the switch in that one is also bad....so im guessing i have to replace that one too.

more than likely i'll just switch around the panic button to the primary arm/disarm switch...in the event i cant find a replacement.

but why did the light stay on and only half as bright, before i changed the battery?

atleast i dont have to feel like a criminal anymore ,when i had to jump in and disarm it...

[Bobken]

[QUOTE]Originally posted by Clipped
[B]ok, put in a new battery and it worked....


but why did the light stay on and only half as bright, before i changed the battery?

Hi,

I tried to explain that in post #6.

In the circuit there will be a device (probably a dropper resistor) to reduce the voltage and current for the LED, which will always (normally) be operated at less than your 12v battery provides. The LED will also give out some light down to quite a low voltage and at a very much reduced current, albeit that the light emitted will be less bright as you found.

Batteries slowly discharge during use, and after a while the voltage will drop to the extent that it will no longer adequately power a radio transmitter circuit adequately, but it is still sufficient to give some light from the LED.

It is as simple as that.

Regards,

[Clipped]

the thing that has me confused is...why the led 'stayed' on but at lower intensity..

when i pressed the button the led would stay on...it would not turn off....maybe a diagnostic mode built in?

[Bobken]

Hi,

Oh, sorry, this wasn't clear to me before.

If the LED stayed on *after* you released the button, that is another matter, and I wouldn't like to guess at the cause of that.

I don't know of any such diagnostic "modes" which would be applicable in a case like this, but anything is possible.

Presumably, you are sure that the switch is properly disconnecting when it is released, as you say that you have changed some of the switches around?
It is worthwile making sure that the LED does always extinguish each time (at least for a few days) as otherwise the battery will not last for very long, and the switch could be intermittently playing-up, I suppose.

Regards,