disarm function not working all else ok

Hi,

I am installing a Carvox King Eagle in an 1999 Dodge Caravan.
Mostly things are going well except that I cannot get the Factory Disarm to work.

I can Lock and Unlock the doors with the Carvox King Eagle alarm now.

I can also ARM the alarm.....but It won't DISARM.

This one's got me stumped. The door has a Lock switch in it as well as a Arm/Disarm switch.

The Caravan utilizes a 1 wire locking system. So, by sending pulses of different current through the wire, it does different functions. I have three of the functions working, but for some reason the Factory Alarm Disarm isn't working and I can't seem to find the answer....yet.

For this vehicle, I had to add inline resistors of various resistances to the wires from the Carvox. But all 4 of these wires connect to the same vehicle wire. The circuit connection in question calls for a 660ohm resistor and that is exactly what I have used. I checked to resistance on that resistor and it is correct. I also checked the output form the Carvox unit and it is also correct.

It may be that for whatever reason, the control unit for the alarm is looking for a slightly different current pulse than what it's receiving and so the recommended 660ohm resistor is not correct for this circuit....Im not sure at this point.

Guess I'll need to devise a way to read that exact pulse in terms of current from the original circuit (the one the door switch is sending which works) to try and match it with a different resistor than the 660ohm resistor I've read that it calls for.

If anyone knows anything about installing aftermarket alarms in Caravns I would appreciate hearing from you.

Thx

Whats the voltage on that wire when you turn and hold the key in the "UNLOCK" position in the drivers door key cylinder?

The resistor is modifying the voltage, not the current - if you can figure out how much voltage is on that wire when you disarm the OEM system you can verify your voltage is correct through the 660 ohm resistor to ground (again by measuring the voltage).

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Kevin Pierson

Thanks Kevin.

I suppose I need to do exactly as you suggest if I'm going to move forward today

Thanks for the reply.

I haven't done that generation of Caravan in 5+ years, but this is what I remember:

If the van has the OEM alarm, you will use one resistance value for lock and arm, and a different resistance value for unlock/disarm. I believe the first pulse on unlock/disarm unlocks the driver door and disarms the alarm, and the second pulse unlocks the other doors. You shouldn't be using 4 different resistance values. You only use the values listed on tech sheets for lock/unlock if the van does not have the OEM alarm. I highly suggest relays. Have the lock and arm output of the unit trigger one relay, and the unlock and disarm output trigger a second relay.

Thanks guys.

The Door Lock and Unlock functions are working perfeclty by the key and by the CarVox King Eagle.

It's the Factory Alarm Arm/Disarm that's giving me fits.

The Factory alarm works perfectly by the key (in the door) so I assume all I need to do is ensure that the proper voltage values are being delivered by the Carvox alarm to the proper vehicle wire.

What I'm NOT sure about is whether or not I should be connecting the wires with resistors for the ARM/DISARM to the SAME wire as I'm connecting the door LOCK/UNLOCK wires.

Everything I've read states that the 1999 Caravan uses a ONE WIRE locking system, but it's ambiguous if that means the alarm arms and disarms the factory alarm via the SAME wire or not.

My ultimate goal here is to use the CarVox King Eagle pager in place of the factory key fob. All I really want the Carvox to do is to lock and unlock the doors (which it is), Arm and Disarm the factory alarm (which it is not), and pulse the horn one beep when arming.   I'm not concerned about using the CarVox's other features at this time.

thanks again!

JWorm] wrote:

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I haven't done that generation of Caravan in 5+ years, but this is what I remember:

If the van has the OEM alarm, you will use one resistance value for lock and arm, and a different resistance value for unlock/disarm. I believe the first pulse on unlock/disarm unlocks the driver door and disarms the alarm, and the second pulse unlocks the other doors. You shouldn't be using 4 different resistance values. You only use the values listed on tech sheets for lock/unlock if the van does not have the OEM alarm. I highly suggest relays. Have the lock and arm output of the unit trigger one relay, and the unlock and disarm output trigger a second relay.

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JWorm,
Thx for the info.
From all I've gahered, all 4 inputs from the aftermarket alarm connect to one single wire on the Caravan. On my 1999, that is a white wire with dark green stripe.
Currently, from the aftermarket alarm I have the lock and unlock wires both conneced to that WHITE/ green wire through resistors and the lock and unlock is working both with the Key in the door AND from the aftermarket remote.

It is only the arming and disarming of the OEM factory alarm that is a problem.

I guess one question might be why and I adding an aftermarket alarm if I have a factory alarm? Well, the aftermarket alarm has a pager that can let me know from up to a mile away if there is a problem. Secondly, I did not get a remote with my pre-owned Caravan and I opted to buy the aftermarket alarm to lock and unlock my doors rather than buying a OEM keyfob from the stealership and paying their "service dept fees" to code it to my vehicle.

If I can just get this OEM alarm arm/disarm to work im good.

i think what is going on, if i am reading your replies correctly is that you are trying to use 4 outputs from your aftermarket unit to control the 4 things separately, all you should need is the lock and unlock signals from the alarm unit, going into 1 relay for lock and 1 relay for unlock. on the output pin 87 or pin 30 whichever you chose, should be a ground signal with the inline resistor 4020 for lock AND arm, and then the other relay output would be the 665 unlock AND disarm, both of these wires going to the wire you are using now. this will give you arm with lock and disarm with unlock.

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To master and control electricity is perfection. *evil laugh*

Am I wrong inthinking you should only use the factory disarm resistance on the unlock side since that will unlock and factory disarm AND use a double unlock pulse.

Thanks for all the help everyone.
It was initially JWorm's post that started me down the ultimate right path. I was trying to connect 4 wires instead of two for unlocking the doors and controlling the arm/disarm. Then racer's follow up.

I incorrectly thought that there were 4 different pulses needed when in fact there were only two that were needed...hence only two wires needed. I did not get it that TWO wires could lock/unlock AND arm/disarm.

I think the ambiguity in theis case arose from the information at another Alarm Wiring diagram site where it was not CLEARLY stated that all 4 wires were not to be connected but, depending on whether or not the vehicle had a factory alarm system, two or 4 wires would be needed.

I guess a good summary for those arriving here later but also lost should know is that on 1 wire locking systems, you only need to connect the UNLOCK and LOCK wires from your after market alarm even if it comes with 4 wires (Lock/Unlock and Arm/Disarm).

Just be SURE to use the correct resistance for your vehicle on those two wires. I used the ARM/DISARM resistances as the Lock/Unlock resistances did not also arm and disarm the system but the ARM/DISARM resistance values do BOTH.

Ok,
It's been a while since I got the alarm working and as someone suggested, I believe I need to install relays on the lock and unlock wires because it seems the functions are getting very lazy (best way I can think of to describe it).

At first for about a month, they unlocked and locked and armed and disarmed fine.

Now, sometimes it wont unlock but I can still hear something happening. It just sounds very weak. It's been getting progressively worse over time so it sounds like the relays in the alarm just couldn't handle the load.

So, I am going to install a relay where I now have the alarm wire directly connected to the car's unlock and lock wires through resistors.

MY QUESTION is ............

Since I'm no longer connecting the alarm's wires diredtly to the vehicle's wires, and instead, will be using a full 12v wire from the vehicle, actuated by the relay, will I use the same value resistors?

For this vehicle unlock requires a (-) negative through a 250 ohm resistor and disarm requires a (-) negative through a 665 ohm resistor. I ignored the arm/disarm wires and only connected to lock and unlock and it has been working to lock/unlock and arm/disarm perfectly....until recently.

So, I connect the NEGATIVE power wire to the vehicles UNLOCK wire through a 250ohm resistor, the other side of the relay contact to POSITIVE 12v, and the relay solenoid to the alarm output wire and either positive or negative......right?

I had trouble following exactly what your question about the relays, but you'd do this:

Get TWO automotive SPDT relays and wire like this:

86 on both relays: constant fused power
87 on both relays: ground
87a on both relays: nothing

85 on Relay 1: Lock wire from remote start, AND arm (or "pulse-after-start") wire from remote start

85 on Relay 2: Unlock wire from remote start, AND disarm wire from remote start

30 from both relays: Run these wires together, run them to the arm/disarm wire on the Caravan, but don't add resistors or connect them to anything just yet.

Now, you asked if you need to change the values of the resistors, now that you're using relays, right?

Well, here's what you do.

Take that 30 wire from one of the relays, strip a little off the end, and hold it against a resistor with your finger. Hold the other end of the resistor to the car's arm/disarm wire, and try your remote. See if it works right.

I like to make a habit of trying it both with the car off, and with the car running under remote start. My theory is that the car's voltage is higher when running, and so you want to check it both ways........just an unproven theory but doesn't hurt.

Now grab 30 from the other relay, put your other resistor there by hand, and try that one too.

Once you've made certain that all works correctly, you can now connect and tape up your resistors in a secure, permanent manner.

P.S. Doing it this way, keeping the resistors separate from the relays.......and tying the resistors down low by the Caravan's BCM.......if you ever have to change a resistor value, it's easy. You don't need to touch the relays again, and don't even need to take the dash panel down.

Wow..thanks Chris!!

Right now, I have to blu/black wire from the alarm going directly to the WHITE/ DkGreen wire at the BCM plug.

Unless Ive made a mistake,,,here is what I believe I need to do.

Anyone ?
Does this look right?

thx

Chris suggested that you test the functions before making it permanent. Ultimately, it should look something like this:

Beautiful illustration and thank you VERY much for the assist!