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.....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.

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. C Renner's Auto Electronix

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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.