Adding Keyless Entry To 2008 Ford E450 Class C

[evolvingpowercat]

Hi, I own a 2008 Itasca Cambria 29H Class C Motor Home on a 2007 model year Ford E450 cutaway chassis. I have added keyless door entry that is working great for me and here are some details.

I started with a keyless door entry system designed for automobiles and light trucks, I used the inexpensive "Lock10" module that uses 315 MHz coded RF signal that is supplied with 2 matching coded keyfob remotes. The module draws less than 10 milliamps in idle mode so it does not cause excessive idle drain on the OEM Ford E450 battery. This module pulses its lock or unlock relay for 1/2 second similar to what one generates when manually pushing the E450 lock unlock door buttons.

This specific module can be found on Ebay as well as Amazon.com. Any module with isolated contact lock and unlock relay "half second pulse to lock or unlock" outputs should work with this modification.

I augmented this with two 30 Amp 12 volt coil Single Pole Double Throw (SPDT) automotive relays. The base module relays will not handle the current load needed for the E450 + motor coach door lock motors. The power relays also have a second major benefit - they allow the modification to be connected to the E450 without running any new wires into the passenger door.

Cost of parts ( module plus 2 Relays ) was under $ 25.

• Two power lock wires from the driver's side kick panel leading into the driver's side door are cut and connected into the modification wiring.
• The 30 Amp Power lock fused power supply wire from the driver's side kick panel leading into the driver's side door is Tee connected into the modification wiring.
• Two black wires leading to ground below the passenger side lock/unlock switch are cut.
• The modification wiring finally is connected to a good ground on the driver's side kick panel.
• Optional: The output from the module that "flashes" the parking lights when the key fob remote is used is Tee connected into the parking light wire that runs down from the kick panel area into the trough along the driver's side door leading towards the rear of the chassis

The wiring diagram is attached as a PDF.

One design feature is that the door lock / unlock buttons will continue to work even if the module dies or is unplugged from its connector so long as the two power relays remain in the modification.

This modification could be adapted to work with any alarm system module that has keyfob remotes that has positive 12 volt pulse outputs to control door locks.

RAS

Manhattan, Kansas USA

2008 Itasca Cambria 29H

2013 Fiat 500C

2008 Cambria Remote Keyless Entry Modification.pdf

[dickandlois]

RAS,Thanks for sharing the information and file with the group!

From looking at the drawing and the way you up dated the PDF file, it looks like this is one of your skill sets ! LOL


Rich.

[evolvingpowercat]

Thanks, I am a recently retired Electrical Engineer, formerly employed by Sprint. Have always enjoyed designing practical circuits for myself and friends to solve problems like this.

It was interesting reverse engineering the Ford Power Door Locks, figuring out how they managed to save a couple cents per vehicle by making the power door locks work with so few wires in and out of the doors.

[dickandlois]

My pet peeve is the use of copper clad steel wire in equipment that is exposed to vibration or areas where it is constantly being flexed.

Been chasing broken wires that would last a long time if made out of 100% cooper.

Bottom line looks good to the bean counters, but the buyer pays a price down the line.

There are a number of recalls in the pipeline just because of poor wire selection.

Rich.