Help with alarm trigger mod

jmorzuch · October 9, 2015

No the point is that I want to use the hood switch as the trigger point to the BCM for someone who just tries the handle on a locked door.

I have ordered some 700 ohm resistors and if I can get this to work I will update the thread.

Ok, now I get it. So all of the handles and the hood go to the same BCM point, so you will just use the hood as the BCM point. Makes more sense now (to me)

crewl1 · October 9, 2015

I think I have this figured out now.

The use of a 700 ohm resistor across the circuit is enough to change the voltage and status of the switch to BCM and trigger the alarm.

I recorded a video so folks can see the theory.

The only thing left now is to identify the best position for the door handle switches and do the install.

It may be a few weeks until I can dedicate the time to do it so I will leave you with this info for now if anyone wants to attempt it on their own.

Video

Diagram

crewl1 · October 9, 2015

Here is a link to the resistors I ordered, they are actually 680 ohms but close enough.

http://www.ebay.com/itm/5-Pcs-Carbon-Film-Resistor-680-ohm-1-2-watt-0-5W-5-/301761755684?hash=item464266fa24

I arrived at this value by measuring the resistance across the hood switch.

The momentary switches I will be using are these.

http://www.ebay.com/itm/-/191248998291?roken=cUgayN&soutkn=oq2eXK

crewl1 · October 16, 2015

I have done the mod for the tailgate now.

I made a bracket from a leftover part of some project (I believe it is a false ceiling hanger.)

It works as a z bracket to hold the switch in position.

The video shows how it works.

After setting the alarm by locking with the fob, when someone tries a handle it will trigger the alarm.

Next step will be to place switches on each of the doors.

crewl1 · November 12, 2015

I finally completed the first door on the truck.

It was a bit tricky to figure out as the handle does not provide a prominent lever action to use to bump the switch.

Instead it uses a cam to pull the door release cable.

After much trial and error I settled on using the cam to pull monofilament line to activate the switch.

I added some hot glue to each knot as a keeper, so the pic looks a bit messy.

The switch is attached to the door handle mount.

Now that I have the approach figured out the rest of the doors should go much faster.

Video link here

crewl1 · November 25, 2015

The mod is finally complete.

The front doors were much more hassle than the back doors as the handles are not as easy to get to as the rear and it is hard to see what you are doing.

I again used monfilament line to pull the switch via the cam and locked the knots with hot glue.

Final video shows switch action and all entry points armed.

DAP56 · December 1, 2015

This is so awesome. Wow good work. I'd pay you to do mine if you lived in CO...

Sent from my iPhone using Tapatalk

crewl1 · December 1, 2015

This is so awesome. Wow good work. I'd pay you to do mine if you lived in CO...

Sent from my iPhone using Tapatalk

Thanks!

mkeddie · December 13, 2015

This is a great mod ....can u post some pictures of where and how u tapped into the bcm

crewl1 · December 14, 2015

I didn't do this at the BCM I tapped into the wires coming off the hood switch.

In the video it is the wires I have the pins stuck in.

you can see the referenced location of the wires.

If you remove the cover you can easily access the switch wires, they are obvious as they are the only wires coming off the hood latch to a connector a short distance away.

Use the diagram above for reference.

You can use wire taps or in my case I cut the wires and added bullet connectors so I could remove the mod if needed.

I used two conductor wire ( I had 14 awg laying around ) and routed from the switch to inside the truck via the main grommet. I did this to be able to hook up all the other door switches.

If you just want to arm the tailgate you should be able to run all the wiring from tail to hood without going into the truck.

Don't forget the resistor, it is the key. For a tailgate only setup you can put the resistor at one of the tabs on the momentary switch or really anywhere in the circuit. It just has to be in the path when you close the circuit via the switch.