Another OPUS 250 question

**jdamb89** · 05-15-2008, 05:30 PM

Sorry to post again so soon guys. I've been trying to get my computer to start with the ignition using the OPUS 250. It isn't working.

So far, as soon as I plug power into the PSU, the computer tries to start immediately without the ignition and fails. The led then blinks twice. I have tried switching the polarity of the green and white wire on the two pins (I think they're in the right spot, the computer boots normally with a normal psu when i connect them with a screwdriver) with no success. My understanding is that the computer shouldn't try to start when it is connected to the power. What is wrong with the install? Is it a bad ground?

Thanks ahead of time for your input.

**DarquePervert** · 05-15-2008, 05:45 PM

Sounds like the IGN line is connected to 12v constant....
Have you measured the voltage on the IGN line with a multimeter with the key in both the ON and OFF positions?

**jdamb89** · 05-16-2008, 05:20 PM

I installed a switch for the IGN line. I had it set to off, with the car off, and i plugged the computer in. The computer still tried to start and failed going to the double blink error. After I had turned the car on, i turned on the switch, and the computer immediately tried to start again, this time failing and going to a single rapid blink on the power supply with a constant light on the MB.

I'm at a loss for what is wrong.

**jdamb89** · 05-17-2008, 05:23 PM

I've done some more snooping today. I can get the computer to turn on if I leave on the original power button and press it 1 or 2 seconds after I plug the system in. So that eliminates the issue of low power from the battery.

Perhaps I have the IGN wired to the wrong spot? It connects to the fuse for the ignition inside the fuse box in the engine compartment.

**2k1Toaster** · 05-17-2008, 05:43 PM

Do as DP said and measure the wire. Blind guesses are not a good diagnostic tool.

If you accidentally wired the +12v constant to the ign terminal of the psu and the +12v switched to the constant, it would do as you are describing. This also means you are pulling all your power from your ignition line which is a bad idea.

Get out the multimeter and measure it.

**jdamb89** · 05-22-2008, 05:51 PM

I checked it with a multimeter.

Off: No current
On: Current

And like I said earlier, I have a switch on the IGN line that I keep off when I plug the system in. As soon as I put the connecter into the OPUS psu, the system tries to start and fails to the two led blink. If I turn the car on after this, it tries to start and fails to an led blink about every second.

**jdamb89** · 05-22-2008, 08:29 PM

Alright....I got part of the problem figured out. Turns out that motherboard has a strange characteristic where plugging in the psu causes it to kind of start and then stop. I can manage that by ensuring it starts properly by pushing the power button after I plug it in. However, after that, when I try to boot it with the car, it still fails to a single blinking led about every second.

My first thought would be low current, but I can make it start with the power button. I'm not quite sure what this blinking indicates.