I was wondering where I would have to tap the headunit into to make it turn on when I have the car being remotely started.

My radio automatically comes on with remote start. I dont know why yours wouldnt. It just turns the ACC on so the radio, and AC/Heater as well as wipers come on if they are left in the on position before turning off the car.

Same here.

When I remote start my car, it's as if my keys are in the ign. (unless someone try's to drive it, it will shut off).

All you need to do it have the radio on when you last shut off your car. Then when you remote start it the radio will come back on. Just make sure you have it turned down.

Better yet you can get an alarm with multiple channel outputs and program a channel so that it kicks on a relay to trigger your ACC power to the head unit. That way you can turn on your head unit without remote starting your car.

whoever installed the remote start might not have hooked up the 2nd accessory wire, which is not needed for remote start purposes. If you want your radio to come on w/remote start or remote, depending on the brand, you could just take one of your additional outputs, and a relay to trigger that 2nd accy. Give us some more info on what kind of remote start you have.

I have the Viper 790XV.. Also.. you know if there is anyway my friend might have hooked this up wrong and cause it to constantly drain my battery where if the car is not started every 2 days the battery would die?

dude, you fucked up. Viper will not warranty their alarms unless they are installed by a certified dealership.

And you should never let your buddies hook up an alarm.

I am aware of that now and I have problems with it.. So what else can I do.. Not much, just something I have to live with.