M1-ATX in dumb mode vs engine cranks

**Meelobee** · 11-23-2005, 08:12 AM

I use a M1-ATX in my setup and have the jumpers set to normal mode. (dumb psu mode) I use a switch on my dashboard to turn it on/off.

When the M1-ATX is in the dumb psu mode should it survive engine cranks?

Cause mine isn't. I've doublechecked if the power outlet in the boot, My multimeter tells me the voltage dips to 10.2v when I crank the engine.

**Meelobee** · 12-01-2005, 08:18 AM

*bump*

Doesn't anyone know this ?!?

When the M1-ATX is in the dumb psu mode should it survive engine cranks?

**Chris31** · 12-01-2005, 08:34 AM

I dont have M1ATX but it should survive the crank. Make sure you have a good connection from the battery to the PSU. There may well be too much resistance in between them.

When the PSU need to operate from 10v due to cranking, it will naturally draw more current to generate the same power output. So make sure you use thick wires.

The M1ATX support guy is here often so he should be able to help you.

Have you tried using the NOT "DUMB" mode?

**ITL** · 12-01-2005, 09:21 AM

never used dumb mode, but mine survives cranks w/ no problem...I don't see why dumb mode wouldn't. Do you have an old battery? Perhaps your battery or alternator is bad or going bad and can't provide enough current.

**Meelobee** · 12-01-2005, 10:04 AM

The battery in my car is fine, at least that's what I should expect from a new battery, I got the car (new) in july.

I'm not using any of the other mode's because the delay's are not good for what I want. I don't want to start/quit the pc everytime i start/quit the engine.

I'll try putting it on a seperate cable running from the battery.

**ITL** · 12-01-2005, 10:52 AM

Originally Posted by Meelobee

I'll try putting it on a seperate cable running from the battery.

That you should DEFINITELY do. Where do you have it running from, now?

**Fusion-One** · 12-01-2005, 10:55 AM

Mine doesn't survive crank either, at 9.7v, tested with a 4 ft peice of 8ga from the battery terminal. =\

Ah well.

**WebDog** · 12-01-2005, 10:56 AM

Originally Posted by Meelobee

The battery in my car is fine, at least that's what I should expect from a new battery, I got the car (new) in july.

I'm not using any of the other mode's because the delay's are not good for what I want. I don't want to start/quit the pc everytime i start/quit the engine.

I'll try putting it on a seperate cable running from the battery.

You can wire a switch to the ACC wire that is a 3 position one is normal acc, aone always on, and off.

**Meelobee** · 12-09-2005, 10:56 AM

Originally Posted by ITL

That you should DEFINITELY do. Where do you have it running from, now?

Sorry for the late reply, currently I use a standard 12v outlet in the boot.

Originally Posted by WebDog

You can wire a switch to the ACC wire that is a 3 position one is normal acc, aone always on, and off.

Can you explain that a bit more? It sounds like something I want.

**ITL** · 12-09-2005, 11:41 AM

Originally Posted by Meelobee

Sorry for the late reply, currently I use a standard 12v outlet in the boot.

I assume by boot you mean trunk. You ought to try running directly from the battery.

Originally Posted by Meelobee

Can you explain that a bit more? It sounds like something I want.

Let me try. The three position switch would allow the following scenarios:

1) Run PC anytime, no matter if car is on or off. You control startup/shutdown.
2) Normal ACC: Ignition controls startup/shutdown.
3) PC is always off.

Wire 1 will be constant 12V. Wire 2 will be switched 12V. Wire 3 will be common ground.

This is something I need to implement myself. I'm just spinning my wheels trying to figure out the best place to discreetly, yet conveniently mount the switch.