Door Trigger, Dome Light Sharing?

Greetings all,

I'm preparing to install a DEI / Clarion / Ungo SR6000 remote start alarm system in a 2001 Dodge Ram turbo diesel pickup with AT.  This is my first alarm install, and it'll also be the first alarm system I've ever owned.  I'm starting out by carefully going through the alarm's installation manual and the truck's wiring diagrams (I have the factory service manuals) to figure out exactly which wires I want to tap into, and their locations within the truck.

This alarm system has a (-) Dome Light Supervision Output to drive an external dome light supervision relay.  According to the installation manual, when enabled, this output turns on the dome light for 60 seconds when the ignition is turned off.  Since the truck doesn't already have factory dome light supervision, I'd like to use this new feature.

This truck also has negative (-) door pins with a common wire between them, so the door pins will easily be connected to the H1/5 Door Trigger input on the alarm system... simple enough.

In trying to figure out the best place to connect the Dome Light Supervision relay, it occurred to me I'd simply use the same wire I used for the door triggers... since of course this wire makes all the dome lights illuminate!

Now this may be a dumb question, but I'll ask anyway to hopefully rule out any problems later...

If I use the same wire in the truck for both the door trigger input *and* the dome light supervision relay, couldn't the alarm trigger itself when the dome light supervision comes on?

Examples:

1. Let's say I turn off the ignition then the dome light supervision kicks on (starting the 60 second countdown), I immediately jump out of the truck, close the door, and then arm the alarm system.  In that case, wouldn't the alarm still think the doors are open because of the dome light supervision still being on?

2. Let's say I'm driving the truck with the alarm armed, I reach my destination, turn off the ignition, then the dome light supervision kicks in.  Wouldn't this trigger the alarm to sound because of the dome light supervision still being on?

I'm hoping someone will tell me the alarm is smarter than than me and will turn off the dome light supervision upon arming, and disarm the alarm when dome light supervision activates.  If not, where or how do I hook up the dome light supervision relay to prevent false triggering?

Thanks in advance and have a great day,

John

PS: If anyone happens to have a wiring chart for this particular truck and alarm system handy... and would be so kind as to post it... I'd be ever so grateful.  I couldn't find one in the forum database or old posts.

I do this a lot and have tried it on the Ram. You don't need a relay for the dome light supervision as the door trigger is nothing more than a wire that drives the factory dome light relay in the BCM. The output on the DEI is 200ma, plenty to trigger the factory lights. Just hook the dome light supervision wire to the door trigger wire and it's done. Some cars that have a factory alarm this may not work on, like Nissan, because the output from the DLS triggers the factory alarm before the DEI gets a chance to turn it off, thus making the factory horn honk once. It should work fine on a Chrysler product tho...

WHy on earth would you ride around with the alarm turned on?????

Got it.  Thanks!

I looked at the installation manual and owners manual again, and while it *is* possible to program door locking and unlocking with ignition (independently of each other), it makes no mention of arming or disarming the system at the same time.

But to answer your question about driving around with the alarm armed... the question was more hypothetical.  I'm not sure I'd actually ever feel the need to do it, but I can see a person might want to as an anti-carjacking measure.

Example: Let's say your driving around town in traffic during the summer with the windows rolled all the way down.  You come to a stop at a light with other cars all around you (no way to move until the other cars do).  A carjacker runs up along the passenger side of the vehicle, unlocks and open the door, gets in, points a gun at you and tells you to get out the driver's side.  With the system armed, the alarm would trigger the instant the carjacker opened the passenger door.

Maybe not the greatest example.  Mainly I just want to make sure I understand exactly how the alarm works in every possible situation up front, to prevent me from making some poor wiring choice now that'll create more rewiring work for me later.

And I probably over-analyze everything. :)

Thanks for your help.

Thanks for the reply Mike,

Boy, I sure hate to disagree with you about the need for an external relay to control the dome light circuit on a 2001 Dodge 2500 Ram pickup.  I have zero experience with vehicle alarm system installation, and it sounds like you have plenty.  But just to double check, I went back and looked at the factory wiring charts again and I'm sure about it... I'll need a relay for the dome light supervision.  The wiring charts show the door pin switches (Dodge calls them "Door Ajar Switches") ground the dome light circuit to the truck body without any indication of a relay anywhere in the current path prior to the switches... which ultimately comes from the battery.

Now on the other hand, the wiring charts do show that the Central Timer Module (under the dash) does tap into the truck's dome light circuit to sense when the doors are "ajar" in order to display a warning on the instrument panel.  But again, I see no relays in the dome light circuit of this vehicle.

Best regards,

John L.

The dome light relay is actually biult into the Body Control Module under the dash. The door pin wires are just a trigger for this relay to make the interior light come on, the interior lights aren't actually getting ground from the switches but the relay. If you really quiet and stick your head under the dash you can actually hear it when they shut off. The relay isn't separate so you won't find it tho. If your not comfortable doing it this way, there's nothing wrong with adding a relay to trigger the DLS, just more work for something that already exists.

We have found that on a lot of cars DEI says to use separate door trigger wires on you can just use the interior light wire to trigger the alarm, some even Dodges. This saves a bit of time diode isolating, but you need to be sure what cars it works on and which ones it doesn't(Caravan is one).

Your theory about the alarm being armed while driving, if the doors igntion lock they won't get in to begin with. Most alarms won't arm if the ignition is on and some even trigger when they see the ignition come on(DEI). Also, you would have to bypass the shock sensor when the car is being driven.

Hi again Mike,

I think I've figured out where the confusion is...

Apparently the 2001 Dodge Ram series of pickup trucks were available with three basic accessory packages: the "Base," "Highline," and "Premium" models.  The Highline and Premium models had added bells and whistles such as a temp display, compass, automatic door locks, heated seats, timed illuminated entry, remote radio switches, speed sensitive wiper control, factory alarm system, etc.  Unfortunately, I only have the Base model, but it does have power windows and door locks.

Now according to the descriptive text in the factory service manual, only in the Highline and Premium models does the Central Timer Control (a.k.a. Body Control Module) control the dome lamp illumination "with timed load shedding."  On the Base model (which I have) it's just a standard dome light illumination circuit where the door pin switches simply ground the dome lamp circuit... no relays.  The wiring diagrams do show the different type of dome light wiring circuits depending on the model.

So we're both right. :)

But relay or not for the dome light supervision, I think I'm understanding that it's OK to connect the door trigger input on the alarm *and* the dome light supervision illumination circuit to the same wire grounding the dome lights in the truck.  Doing so will not cause false triggers or error states in the alarm... at least it shouldn't.

In the case of this particular alarm (a Clarion "Ungo SR6000" manufactured by DEI), it features a setting to enable or disable "Armed While Driving (AWD)."  The installation manual states: "In the default setting (Armed While Driving), the system can be armed with the ignition on.  When armed, the ground-when-armed is not active and the sensors are bypassed.  The door triggers will remain active."

The only reason I can think of for this AWD feature is to deter being carjacked when driving a vehicle with the windows rolled down.

Best regards,

John L.