1991 MR2 Turbo, several interesting challenges

Hey everyone - perhaps you can help me...

I am installing an alarm for the first time.  I am reasonably knowledgable about electronic components, how to use my multimeter, etc.  I have done several car audio systems etc.  The alarm I am installing is a Code Chapman IV-F65 (the new version of the SureStart LX).  It has a built-in shock sensor.  My car is a 1991 Toyota MR2 Turbo (5-spd manual tranny), and it has a turbo timer (idles the engine w/o the key in the ignition for a couple minutes to cool off the turbo).  This presents a few interesting challenges:

1.  I would like to be able to wire up the remote start  to work with my manual transmission.  I always leave the tranny in neutral when I get out of the car anyway so the turbo timer can do its thing.

2.  I would like to be able to arm the alarm when I get out of the car, with the turbo timer keeping the engine running.  One problem I see here is that when the turbo timer shuts off the engine after a couple minutes, the vibration from the engine shutting off shakes the car, thereby likely triggering the shock sensor.  Is there a way to have the alarm arm against everything but the shock sensor, then enable the shock sensor a few seconds after the engine shuts off?  If not, is there a way to have the car arm itself a few seconds after the engine shuts off?  BTW - as far as I know, the turbo timer does not have an output signal indicating its current state.

Any help would be greatly appreciated!

Many thanks in advance,

Dave

If your good with relays you could use the output from the timer to the ign. input on the alarms. Then set your alarm for passive arming 30 sec. later after the timer shuts down the alarm will arm. Another possibility would be to use the relay to break connection on the sensor to the alarm any time it is running.

One more option , if it is remote start don't use the timer and just use the remote start take over feature. With the key in, remote start take over then get out arm the car, the alarm won't read shock sensor while the remote start is in use.

think about it

Chris

   There may be a feature on your alarm to set the timing on an "auto-arming" feature. At either 10, 30, or 60 seconds after the car is shut off and last door closed, the alarm will arm itself. This feature is available on Omega research products (Excalibur, K-9, etc).

   Another option is to shut off current sensing feature on the alarm, then use a delay timer to control power to the shock sensor. This is a relay which closes after "X" period of time when triggered. Go to your local mobile electronics retailer and they can help you get one. You'll probably get a blank stare if you ask somebody at Circuit City - don't waste your time.

   I'll think this one over a bit and eat dinner, maybe I can come up with a better answer. Nice choice in cars BTW - I'm a HUGE Toyota nut!

   Dave

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   There has to be a wire somewhere which shows voltage when the turbo timer has the engine running. The Toyota FSM-Engine has a wiring schematic. I'd look there first for a possible connection to the ignition switch.

   You could also find any unusual wires at the ignition switch and trace them (in the car and on the schematic), then test them for voltage. Using this wire to control arm/disarm functions and shock sensor power would be ideal.

   I would use this wire to control ignition sensing on the alarm module. If it's 12V+ a pair of diodes and tap it into the ignition wire on the module. If it's ground a relay and 12v+ will switch it.

   The turbo timer wire could be also be used to control a relay for power to the shock sensor.

   There has to be such a wire. Otherwise, how does the ignition stay on and then shut off at the appropriate time? I would spend some time researching before I went any further with the install.

   Dave

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I'd suggest checking with the Mr2 group at http://board.mr2faq.com

It's been done a lot of times..  The idle doesn't usually set off most alarms, unless the impact level is set poorly.

Depending on the Timer, if you cut the (I *think*) blue wire to it, it will no longer keep the accessories on when counting down, which is what you want to do.  Without ACC on, the alarm will arm like normal.

Regards,

Dmitri Pappa

Generally, if the alarm senses power on the ignition wire, you're not allowed to arm it, or operate the remotes.  You'l probably need to use the turbo timer's ignition output to trigger a relay, to interrupt the ignition wire going into the alarm---that way, you can still arm the system while it's running under the conrol of the turbo timer.

When the turbo timer is going, does it leave the radio operational as well?  If not, you could perhaps use the car's blue/red accessory wire as your alarm's ignition input--this way, the alarm will only see power when you physically turn the key on.  However, if this wire also serves as the remote starter's ignition output, you may run into other unforseen issues.  But it's still a thought.

Since your shock sensor is built in, there's not a lot you can do with it.  Try to see how high you can set it before the motor sets it off--you might find a setting that works.

If not, buy an outboard shock sensor.  Instead of hooking its ground wire to true ground, hook it to one of the car's ignition wires.  The ignition wire will behave as a ground while the car is off, but will become positive with the motor running---and the shock sensor will only work when it has a ground---therefore it will be ignored with the motor running.