Connecting aftermarket alarm to factory alarm

[1986911]

Have any of you ever operated your factory alarm through an aftermarket one?? I have a 86 Targa with the factory alarm. I want to have my alarm (autopage rs-1000) operate the factory alarm. My plan is to interrupt the 2 wires going to door mounted key switch. Since I do not have the factory key I really don't know if this would be a good idea, is it worth it??

I would like to know the polarity of the wires going to the factory alarm switch, does it just go to ground when you activate it? My autopage has a wire that goes to ground (500 ma) once I arm the system. I would use this to mimic the operation of the alarm key. This would be the starter kill section of my autopage, the rest would be installed as a usual alarm, shock, doors, flashing lights, infrared for parking topless!, siren and power door lock operation.

I have read here that the factory alarm disables the car via the DME, this is exactly what I am looking for, no spark and no fuel. IMHO the less wires disturbed in this area the better.

I will post pictures of the whole install, I plan to start this weekend.

[DRACO A5OG]

You read correctly, OEM alarm will kill the Fuel Pump via DME and set off the OEM Horn when tripped.

Please keep us posted,

I've installed the Black Widow for remote doors locks and markers. It would be nice to be able to enable the OEM Alarm.

[911pcars]

Ambitious. If you go ahead with this, plan to have an override procedure in case the system decides to go south. You will then want the opportunity to start the engine and go home without the alarm brain saying, "I'm sorry Dave. I just can't do that."

Sherwood

[York]

From looking at the wiring diagram in the Bentley manual, it looks like the door switch does not go to ground. It appears to switch to a different resistance value and feeds to the anti-theft control unit. I have my aftermarket system tied in to the power door locks, and would like it to actuate the factory alarm also. Maybe someone will post a solution.

[RoninLB]

I would keep both systems seperate.

maybe a hidden toggle switch to replace the door alarm lock ?

[1986911]

Originally Posted by York

From looking at the wiring diagram in the Bentley manual, it looks like the door switch does not go to ground. It appears to switch to a different resistance value and feeds to the anti-theft control unit. I have my aftermarket system tied in to the power door locks, and would like it to actuate the factory alarm also. Maybe someone will post a solution.

I just got a copy of the alarm diagram page, you are right there seems to be a resistor in the switch. I am going to measure it tonight to get the value and buy the equivalent resistor at radio shack. Hopefully this will do the trick. Thankfully it does go to ground. If anyone knows the resistor value please chime in!!

Thanks

[RoninLB]

Originally Posted by 1986911

I
,
a resistor in the switch.
Hopefully this will do the trick.
the resistor value please chime in!!

wild guess is that the resistor is on a motor switch to prevent contact damage when the switch is opened?

[T77911S]

i use to do electrical work on cars for a living, only for a short while. i would not install an aftermarket alarm. they cause more problems than anything. do a search here on car alarms and problems they have had. in fact, just recently disabled my brothers because it was causing intermittent no starts, this after he replaced the ignition switch, since it was a common failure for this car anyway, and changing a starter on a G50....twice! if you just want all the little beeps when you set it, dont connect the disabling features of the alarm, that is how i left the one in my brothers car.

[KFC911]

Originally Posted by T77911S

i use to do electrical work on cars for a living, only for a short while. i would not install an aftermarket alarm. they cause more problems than anything. do a search here on car alarms and problems they have had...

+1. I disabled the aftermarket alarm on my 911 (which was a hack job installation imo), but left the flashing LED intact (so it appears to have an alarm). If "they" want it, they'll get it, and car alarms going off don't even turn anyone's head anymore .

[RoninLB]

Originally Posted by T77911S

. i would not install an aftermarket alarm. they cause more problems than anything. do a search here on car alarms and problems they have had. in fact, just recently disabled my brothers because it was causing intermittent no starts, this after he replaced the ignition switch, since it was a common failure for this car

when I installed a Viper alarm I found the "no start" relay wires were a smaller diameter than our yellow solenoid wire. The path is long enough with its associated voltage drop without another constraint.

I haven't upgraded the relay and its wiring yet. I'm going to install the 75 amp relay that was sold with the Bosch stamp. I use it on my headlights and it's a good unit.

[T77911S]

most are hack jobs, may be a lot of the problem. they may also be using inferior (cheap)components too like Ronin said. you put in a small gage wire to the starter, plus another relay, and you are just asking for hot start problems.

yeah, if they want they will get it. whats to stop a guy with a tow truck from hauling off an alarming 911?
i think some people just like to hear the beeps when the alarm is set, another way to get attention. always cracks me up see some kid get out of his GEO and set the alarm.

i would only consider one as long it was not dissabling to the car.

[DRACO A5OG]

Great points but is there a way to make the mechanical key switch to switch off of a aftermarket alarm/remote?

I can't see why a component such as the trigger for the horn or dome light can nto be adapted to become the switch for the OEM alarm.

When I have my top off I manually turn on the OEM alarm but would like to enable remotely with my Black Widow remote.

Currently, my Black Widow only handles the remote locking/unlocking, flash of the markers and Red LED. No horn, dome light or siren.

[81turboporsche]

once i figure out how to get a new key for the unit i pulled out of my door end i will probably get an alarm system, any recommendations i dont want a honda civic style one something a bit less obnoxious

[RoninLB]

Originally Posted by 81turboporsche

alarm system, any recommendations

pelicanhead "bell" is an alarm and audio pro

give him an e-mail or PM



I use Viper and never a problem but bell is a guy who deals with stuff all the time.

[81turboporsche]

cool thanks

[1986911]

Originally Posted by DRACO A5OG

Great points but is there a way to make the mechanical key switch to switch off of a aftermarket alarm/remote?

I can't see why a component such as the trigger for the horn or dome light can nto be adapted to become the switch for the OEM alarm.

When I have my top off I manually turn on the OEM alarm but would like to enable remotely with my Black Widow remote.

Currently, my Black Widow only handles the remote locking/unlocking, flash of the markers and Red LED. No horn, dome light or siren.

Draco, I posted this about the factory switch:
"No Cut" method for bypassing factory alarm

The key has a resistor inside that tells the alarm brain on or off. It was a bummer!
I am sure some resistors could be wired but thats beyond my ability.
Does your black widow have any type of output when armed ??

[1986911]

Originally Posted by 81turboporsche

once i figure out how to get a new key for the unit i pulled out of my door end i will probably get an alarm system, any recommendations i dont want a honda civic style one something a bit less obnoxious

81 turbo, check out the link I supplied to Draco, it might give you an idea of which way to go. I bough an autopage rs-1000 on ebay new for around $200. Its best feature is a one mile pager range.

http://www.autopageusa.com/t_inside.cfm?action=products&catID=1004&prodID=fc5a9b72-bafd-4243-9355-ebe9de1a12be

I have another autopage on my daily driver and the pager works!! I was at a Lowe's buying some plants and it alerted me to someone breaking into my truck. I saw the scumbag in my truck and and scared him away. He dropped my radar detector and house keys before running away.

You can program it not to chirp and to operate the factory alarm horn as the siren. This should eliminate the civic style issues.

Good luck!

[DRACO A5OG]

Originally Posted by 1986911

Draco, I posted this about the factory switch:
"No Cut" method for bypassing factory alarm

The key has a resistor inside that tells the alarm brain on or off. It was a bummer!
I am sure some resistors could be wired but thats beyond my ability.
Does your black widow have any type of output when armed ??

Oh that does suck

Well here is the unit from Black Widow:

BW-854 - 4-BUTTON VEHICLE SECURITY SYSTEM

Not looking for a full-blown security system, but want the convenience of keyless entry and the peace of mind an optional starter defeat feature, then the BW854 is for you. The BW854 can flash your parking lights, lock and unlock your doors, and even open your trunk or hatch at the touch of the button. Using an icon labeled four-button transmitter, you can have total control of your vehicle from up to 75' away.

Features:
• Two 4-button Extended Range Transmitters with Dedicated Buttons for Lock, Unlock, Trunk Release, and Panic
• On-board Relays for Door Locks, and Flashing Parking Lights
• LED Status Indicator
• Valet Mode
• Passenger Unlock Output
• Trunk Release Output
• Starter Defeat Output
• Horn Honk Output
• Dome Light Output
• Programmable Ignition Controlled Door Locks
• Programmable Double Unlock Pulse
• Programmable Chirp Delete
• Programmable Extended Pulse Door Lock Output
• Programmable Passive Starter Defeat

Accessories:
• Window roll-up module (WRM-2)
• Trunk release module (TR-100)

Here is their Wiring Diagram: http://www.blackwidowsecurity.com/currentpdf/bw853%20complete.pdf

[1986911]

Draco, you are good to go with your black widow. All you need is behind your blower motor in the trunk. You just need 1 relay.



Your orange wire (ground when armed) goes to the 85 terminal on the relay. You hook 86 + 87a to where pin # 15 (switched power) would go on the factory alarm harness then 30 from your relay goes to the pin where 87a (hot lead to DME relay) would connect to your factory alarm harness. You are basically dictating when the DME gets power.



To do the above you need a standard 5 pin relay with the standard starter kill harness that has a diode.

If you wanted to get creative you could wire your BW's brown wire (horn output) to a relay.

You will need one more relay, you can make the harness on this one with insulated female solder-less terminals.

On the factory alarm harness the 30 plug is always hot, it powers the factory alarm horn (Hn). Wire your brown wire to #85 on the relay then connect 87 and 86 from the relay to where the 30 pin would connect on the factory alarm harness ( constant power). Lastly the 30 leg from your relay goes to the Hn (horn) pin on your factory alarm harness.

When you are done it will look like this




Last thing, you need to connect the 2 #61 wires in the factory alarm harness to each other. This completes a circuit for the charging system. All of this is done without having to cut a single factory wire. You can't beat it.

Good luck

[DRACO A5OG]

Sweeeeet!

Do you have a parts list?