trunk output for defrost?

Can I use the trunk pop trigger to activate my rear defrost on a 92 Mitsubishi 3000gt, and or on a 99 caravan?

depends on the circuit in the vehicle... most newer RS units have a dedictaed defroster output.... i would recommend using that.....

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Kevin Gerry
Certified Electronics Technician
MECP First Class Installer

Owner/Installer
Classic Car Audio
since 1979

no dedicated defrost lead, but the optional output for trunk is programable. as long as I hold the button, or 10 seconds, or constant.

check this out and see if it will help

https://www.the12volt.com/installbay/forum_posts.asp?tid=65562&get=last

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JUST ONE MORE AMP!!!
hu,alpine cva 1005/dva 5205
sound processor,symmetry(first one).
sub amp,power 1000 the terminator.(1992).
subs,spl comp dual 1 ohms.
punch 150hd on a 10" ev.
alotofhighs

Were you looking for a timed output like the other fellow?
If you just want to control it using the remote, then there's no reason why you couldn't program your trunk output for constant latched mode, and use it to drive a relay suitable for the defroster, in a ground switched (-) configuration.
Just wire up the relay coil so that it can only be energized when the car is actually running, because you don't want to leave any chance that you might accidentally hit the button and latch it on. Even if the relay contact's aren't powered, just the power draw from the relay coil can drain your battery over time.
Wire it up so the relay coil can only be energized when the car is running, and it should be fine.

Not sure, I've done a boat load of alarms and starters i my day but never did a defrost. I would prefer it to come on with the optional output so it isn't on every time I remote start. That would suck in the summer. It is a - 500ma lead programible for 10 second, constant, or as long as I hold the button. I also know that my car requires a momintary pulse to activate the defrost. it is a momintary push button in the car.

Well, if you could get access to the contacts for that momentary push button, that'd be the best thing, since it's probably already a timed defrost period.

Then you can program your control for the momentary mode, and run a relay with it, connecting the relay contacts across the defrost button contacts. When you remote start and you want the defroster on, you can push the trunk release and have it switch for 10 minutes or whatever it normally does.

If you want to run the defroster, it's best to do it with one of the remote start wires. You can wire a toggle switch inline to disable it in summertime - much easier than running it on its own channel, in which case if you'd accidentally activate it with the car off a few times it could drain your battery.

Also, I've done several defrosters and I've found that it's usually easier to get at the power wire to the defogger grid than it is to find a wire you can momentarily pulse. Every car I've done had some sort of relay to power the defogger, so what you can do is use your own relay with the power input and output wires from the factory's relay. I can give you more specific info if you want.




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C Renner's Auto Electronix
My service is cheap, quick, and good - pick any two

yes please, some detailed info would be great.

So , I got it working. I used the 3rd channel output set at a pulse tied directly to the pulse triger wire at the switch. Doesn't come on unless the car is running and the timer works as it should.

thankx for your post to explain how you got it to work and as the sounds of it. it wasn't that hard. sometimes things get turned into difficult ones. but what count is that it works and works right. what kind of rs and did it work for both vechiles? things that might be useful to this site. thankx again

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JUST ONE MORE AMP!!!
hu,alpine cva 1005/dva 5205
sound processor,symmetry(first one).
sub amp,power 1000 the terminator.(1992).
subs,spl comp dual 1 ohms.
punch 150hd on a 10" ev.
alotofhighs

I only did it on the 3000gt, haven't tried on the caravan yet. Both units are trc zr-24. Odd units, website says alarm rs combo with manual trans support, but comes with no siren wire or shock sensor. Other then that they have all the hook up requirments as a combo. Who knows, for 30 bucks a piece who cares. Too close to x-mas to spent big on this stuff.

Oh, and it works just like an alarm also. When you lock it via the remote the hyper blue led blinks.

As far as that caravan, cnj, I haven't done a defroster on one of those, but I did a 2002 sebring sedan. On that sebring, there wasn't a wire available that you could momentarily pulse; the defroster switch just sent a signal to the body control module, which activated a relay to send power to the defogger grid. I used my own relay, controlled by the remote start unit.

It would be safe to guess that the caravan might have a similar setup. If you pull the HVAC control panel off and find a wire that you can pulse, that obviously is going to be the easiest way to do things. If not, just listen for the relay clicking when you're turning the defogger on and off.
Once you've got that relay, see which wire on it is switched to ground or 12v+ to activate it. If you can find a ground switched wire there, you can use a constant (-) output from your r/s to drive it(perhaps a 2nd/3rd ignition (-) output, or a 2nd accessory, or the status output).
If you can't find a ground switched wire, you can use another relay to power it. Hook it up as follows:
85 - negative output from r/s brain
86, 87 - power supply to factory relay
30 - defogger grid power wire.

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C Renner's Auto Electronix
My service is cheap, quick, and good - pick any two