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View Full Version : The final solution to Alarm/TT install



aresix6
06-05-2005, 11:26 PM
Hey guys, here is a post of mine I put on Evom.net. I'm posting the link here to help any of you guys out...hey, just lookin out for fellow my Evo owners.

http://forums.evolutionm.net/showthread.php?t=142227

LEVIII
06-06-2005, 07:56 AM
Nice


Ive always hooked the alarm IGN wire to ACC in the car and the + (either 85 or 86 on a SPDT) triggerside of the starter kill relay to the key side of the starter. But I have only dealt with DEI and no other brands, so Im not familiar with the black widow.

aresix6
06-06-2005, 09:01 AM
hmmm.that's actually a good idea, one less relay to deal with. That is basically the same thing I did. You've hooked it up to the same power sources. My only concern is, w/o diodes, how did you isolate the 12V signals from each other? From the way you describe, if you were to start your car, the components that are tied into the ACC would not disengage because as you put the key in the start position, you are backfeeding voltage through the ACC and continuing to power the accessories as your starter is turning over. That might not be too good of an idea because the starter draws alot of current and COULD adversely effect some of the other components when their voltage drops too much while the starter is engaged.

Anyway, you are onto something, though. In the future I might just use your hookup method, only putting diodes in the lines to the IGN sensing wire of the alarm.

LEVIII
06-06-2005, 09:19 AM
I think I follow what you said but I mean



Normally a starter kill relay in an alarm has 4 wires.

85)Ignition to the alarm and splits to the car also.
86)Ground when armed
30)Key side of starter wire
87a)Starter side of starter wire
87)unused


When I install an alarm in a turbo car with a TT I have always redone the the starter kill relay like

85)key side of starter wire
86)ground when armed
30)key side of starter
87a)starter side of starter wire
87)unused

and then I take the wire coming form the alarm brain that needs and IGN input and hook that to an accesory.


In doing this it should not power any acc during crank.

aresix6
06-06-2005, 09:42 AM
hmmm...I just drew out both schematics as you describe them and to be honest, that still would not work in giving the alarm and unbroken signal to the IGN sensing wire.

In your version, you are basically using the starter signal (from the key side) to engage the coil of the relay and if the alarm is armed, you would be unable to start the cr because the coil is energized, switching 87a to 87, which open. Your diagram works fine for defeating the starter, but still does not solve the problem of giving the alarm an unbroken signal. You are tapping your IGN source to an accessory, which is the same thing as my initial try of tapping into the ACC wire. The problem there is, that when you move you key from ACC to ON, the ACC stays energized, but in order for the starter to recieve optimum power, when you move your key from ON to START, the ACC disengages. At this point, since your alarm IGN sensing wire is hooked up to an accessory, it will not be receiving a signal at all and your alarm now thinks the car is off. It is just momentary, mind you because as soon as you move the key back to the ON position, the signal returns.

This would work, but would cause problems for some minor things like auto-door locking, etc.

I think I'm probably splitting hairs here. There are a million ways to get an alarm to work but keeping the IGN sensing wire happy by ensuring an unbroken signal maintains full functionality of at least my particular alarm.

But I think I can still use your model in the future, only varied slightly...thanks...

LEVIII
06-06-2005, 05:21 PM
I see what your saying but ign controlled locks take longer than that to engauge so it actually doesnt affect anything on DEI alarms. Im not to sure about other brands though. But as for DEI I am posotive as I have done it several dozen times.





Besides that I hate ign controlled door locks and alway try to talk the customers out of that feature.

aresix6
06-06-2005, 05:40 PM
good point...

I kinda like the ign controlled locks, although I couldn't really tell you why...LOL