Powered up! Remote central locking.

[akida]

Hi everyone.

As a Ford owner I am often left in awe at the distance that other people can operate their remote central locking. I often have to be within about 10m of my car in order to operate the central locking. I have seen others work at about 30m.

My question is, while maintaing the current central locking system, can I amplify the output of my remote?

Obviously I would have to use a larger battery like a AA or something and I would need to purchace/build an amplification circuit, and then house the lot with 4 buttons.

I have an AUIII which has a 4 button shield shaped remote. I keep my keys on a clip so if the device doubled in size I wouldn't be real worried.

Thanks!

 

[CocaCola]

Look up the location of the antenna in the car, chances are real good that relocating it to another location will improve range... The antenna in the car is likely placed where it was convenient to place for an accepted range, not in the most ideal location to optimize range... Also there might be aftermarket antennas that will work to improve range, they should be designed for the same frequencies as the remote, but they don't necessary have to be door remote antennas...

 

[akida]

relocating it to another location will improve range

What is a good location? Obviously outside the car qould be optimal, but short of that where would be a good location that would keep it protected?

but they don't necessary have to be door remote antennas...

I like the way you think Now to find out the freq of the remote and an antenna to suit.

Thanks CocaCola!

 

[CocaCola]

What is a good location? Obviously outside the car qould be optimal, but short of that where would be a good location that would keep it protected?

The really depends upon your car, if it's a steel body the higher and out of the main steel structure is ideal... Possibly behind a plastic body panel? Possibly split out to a front and back antenna behind the front and back bumper covers?

The year of the car might be a concern, newer cars use different frequencies that work at better ranges, but swapping out the entire system might be troublesome depending on the car...

FYI I swapped out the entire system on my Corvette for the newer radio frequency and got much better distance... It was a costly swap out as not only did it require a swap out the radio and antenna in the car, but it also required me to swap out all four tire sensors that use the same radio system... And of course new keyfobs, it was about a $600 dent in the pocket and it was only that cheap because I got a good deal on a used radio out of a totaled car... In my case worth it, as it improved performance, but also the fact that the 'old' tire sensors that were dying in my car were $150 a pop to replace vs $50 for the new version, so either way I was out $500 - $600... For me I was also lucky that GM only changed the plug when they upgraded to new radios in the newer years of the car, they left the communications from the radio to the computer and dash the same...

I like the way you think Now to find out the freq of the remote and an antenna to suit.

It should be stamped right on the back of the remote along with the FCC (or regional equivalent) compliance number that you can cross reference with a quick Google search if not stamped directly...

 

[akida]

Did I mention I live in Aus? The back of my remote doesnt say much,

I've been looking around and have worked out that the BEM (body electronics module) controls the central locking but I have not found an external antenna for the unit. I couldnt find any information on a location or for a replacement antenna.

Perhaps I could wire something into internal antenna contacts?

I did find information that the transmitter is good for up to 10m which is consistent with what I get.

Do you know anywhere I can get a wiring diagram for the BEM?

 

[CocaCola]

A car forum specific to your car is where I would start if you can find one...

If the radio in the car is only using an internal antenna, yes you can hook up an external if you can map out the circuit...

 

[donkey]

coca colasidea is right and I am worse at cars than electronics... but if you give me a make and model I might be able to find a gregorys manual or something online that might hint at a good location.... oh and fords kick butt all over holdens... you made a wise choice
anyway from a security aspect have you seen the new little thing happening around sydney... well its happened for years but its seems more regular... people piggybacking your lock/unlock codes. they take a transmit of your data and the next time you are at said location they simply retransmit code to unlock... depending on make of car it may have a rolling code or it may not. having it transmit short distances is good for aanother reason too... at 30metres youmight not see or hear if the door actually locked (especially in high traffic or near construction sites) so being close is practical there. also if you are 30metres from you car and youunlock it how long will it take someone to steal said car compared to how long it will take you to get to it... for example straight after you fuelled it?
there is a good reason to keep the range small and you obviously have the requirement to go further. I am willing to help but I will warn you its something to consider especially if its your only mode of transport

 

[davenn]

The 433 MHz area is a common freq for door and other wireless remote units

Dave

 

[akida]

if you give me a make and model

Ford Falcon AU III. I believe its late 02.

from a security aspect have you seen the new little thing happening around sydney...

Wont affect me, I live in canberra and everyone has a more expensive car than I do

at 30metres you might not see or hear if the door actually locked (especially in high traffic or near construction sites)

I'm a tradie used to noisy environments so I always look for the double flash of the blinkers. I more or less want to increase the power so that I can lock the car from the front door to my house as my family is significantly slower at getting out and closing the doors and unlocking the car as I'm usually the last one out to lock the doors. This is not always an issue but half of the time I can't lock/unlock from my door as I am at the edge of the range, very annoying.

if you are 30metres from you car and you unlock it how long will it take someone to steal said car compared to how long it will take you to get to it...

I wouldn't unlock the car at 30m for myself to get into it as it automatically locks itself If you dont open the door whithin a certain time frame.

 

[CocaCola]

I'm sure the BEM varies from car to car, but if you look at this site that has some pictures of the BEM circuit boards you will see a small inefficient PC board loop antenna... Take that poor antenna and factor in that I gather these are mounted under the dash fully inside the steel structure of the car it's no wonder that you have limited range...

http://www.carmodder.com/doc-ford-falcon-ef-upgrading-the-body-electronics-module-d37m1.html