How to keep your invertor alive while cranking.

MiniRX7 · 02-17-2004, 10:34 PM

Hi guys,

I posted a while back about my X-BOX dying during crank as a result of the accessory line shutting down.

Upon advice from people, i finally made it happen.

First, I tested to see if my invertor will stay on if hooked up directly to the battery during crank. And yes my X-BOX does stay on.

So here's what i did.

I found the accessory wire at the ignition. THere is also another wire at the ignition which provides power during crank and on the ON position.

You need these two wires to keep the invertor on.

What you do is you need dioides on each wire to ensure current doesnt flow backwards (or else you may get messed up crap happening, IE dash lights/climate control coming on while in accessory).

Wire the other ends of the diodes together to a fuse (1amp or so is what i used) incase something shorts somewhere (could blow your ingition if you shorted your ignjition).

Then run this one wire to a relay to switch your invertor.

Now in my car, when i have the car in accessory or running or cranking the ignition, my INvertor stays on. When i turn it off, my invertor goes off.

Finally i can fill gas in my car while leaving my xbox running to play movies/music. and i can crank it and it will still stay running.

ED

R3l0ad · 02-17-2004, 11:18 PM

I would assume it would be very similar to keeping any computer w/ out an opus alive during a crank.

for tank circuits

MiniRX7 · 02-18-2004, 12:44 AM

But there is no TANK in this circuit

eCar™ · 02-18-2004, 01:19 AM

Why do you need both wires? You got the acc line that stays hot during crank, right? Why would you also need to be connected to the acc line that is off during crank?

MatrixPC · 02-18-2004, 09:34 AM

This has nothing to do with tank circuit. This is how to keep the circuit stay hot while cranking. In some/most cars, the ACC line is cut off during cranking but the IGN wire is hot. This is why in those cars, the radio shut off while the key is in the crank position.

So if you hook up an inverter or anything that doesn't have the time delay cut off, the device you connect to will loose power during that couple second cranking.
To have the wire stay hot when the key is in ACC-IGN-START, you need to combine the ACC and IGN together because IGN is hot during crank but not ACC. When combine the 2 together, you need diodes on both wires to prevent back flow.

I am not sure how Opus shutdown controller part work but if it start the shutdown sequence at the moment its ACC input lost power, then you have problem if you connect its ACC input wire to the ACC line of your car. Because the car ACC is cut off during cranking, when you start/crank the car, the shutdown controller will shutdown the machine. let say if the opus SDC has some delay in its ACC input then you are fine to connect to the ACC line. By this I mean if the ACC input line is cut off then hot again within 10 sec (or whatever), the SDC will not going into its shutdown sequence.

If you want your radio to keep stay on during cranking, you can use this method too. On the back the radio is connect to the ACC wire, take that out and connect to the combine wire instead.

MiniRX7 · 02-18-2004, 09:38 AM

Yes, I belive it was you Matrix PC that helped me with this. Thank you very much for your advice. this setup works TRUE WONDERS for my XBOX multimedia system. I would buy you a beer but your too far. Whats your shipping address LOL>

ED

Quote: Originally Posted by MatrixPC

This has nothing to do with tank circuit. This is how to keep the circuit stay hot while cranking. In some/most cars, the ACC line is cut off during cranking but the IGN wire is hot. This is why in those cars, the radio shut off while the key is in the crank position.

So if you hook up an inverter or anything that doesn't have the time delay cut off, the device you connect to will loose power during that couple second cranking.
To have the wire stay hot when the key is in ACC-IGN-START, you need to combine the ACC and IGN together because IGN is hot during crank but not ACC. When combine the 2 together, you need diodes on both wires to prevent back flow.

If you want your radio to keep stay on during cranking, you can use this method too. On the back the radio is connect to the ACC wire, take that out and connect to the combine wire instead.

eCar™ · 02-18-2004, 09:46 AM

I still don't know what you needed the diodes for.

MatrixPC · 02-18-2004, 09:57 AM

Quote: Originally Posted by eCar?

I still don't know what you needed the diodes for.

If you not using diode, there maybe some stupid things going to happen to your car. Car makers design to cut off the ACC line while cranking is to minimize electrical usage (radio and other stuffs) so that the starter can get all the juice from the battery to start the car. If the ACC line is not cut off, the battery voltage can drop very low and the car will have a hard time to start.
Using diode on the ACC line keep all circuit on the car's ACC line off during cranking.
Using diode on the IGN line keep all circuit such as fuel pump, ECU, AC and other off while the key is in ACC position.
The combine wires with diodes keep the car's electrical system remain AS IS.

eCar™ · 02-18-2004, 04:47 PM

I should have worded that differently. Really I am wondering why you need to connect to both wires. If you only connect to one, you don't need any diodes.

You say you have 2 wires. the first has power when the key is in the on position, but has no power during crank. The second has power when the key is in the on position, and during crank. Why connect to the first wire at all?

MiniRX7 · 02-18-2004, 05:28 PM

Because, if you plan on running the system with the KEY on the ACCESSORY position, ie. listening to music with the engine off... you need to keep the accessory line to maintain this.

Ignition/Crank wire does not provide power on the accessory position.

or else the only way your invertor will stay on is if you leave the car on the ON position.

TRUST ME.. you need both wires. and you need diodes. Or else you will have your heater running while your key is in the accessory position. Which the car manufacturer tried to prevent.

ED

eCar™ · 02-18-2004, 05:35 PM

OK, I see it now. Sorry for the confusion.

Pudge · 02-18-2004, 05:50 PM

Quote: Originally Posted by R3l0ad

I would assume it would be very similar to keeping any computer w/ out an opus alive during a crank.

for tank circuits

Dude, he just told you how to do it.

89Excess · 03-22-2004, 11:11 PM

Sorry to resurrect this thread, but would anyone have a diagram/schematic/pic of this set up? I am considering doing this to my radio as the cut off gets very annoying when you are trying to listen to a good song.

Thanks,
Joe

euro320i · 03-23-2004, 05:55 AM

Take a look at www.cartft.com.

I haven't tried it but looks like the implementation is the same. They also seem to have lot of other interesting Car n Computer Stuff.

Enforcer · 03-23-2004, 07:56 AM

Just wire the inverter straight to the battery, with fuses in between, takes the hassle out of which wires to connect.

thats how mine is wired, no probs during cranking at all