fuse blowing

**PharmD Heel** · 04-01-2007, 01:23 PM

Got a problem here I haven't been able to figure out. I've had my computer in the car since August with no problems at all. There's an in-line fuse holder attached to the power wire with a 10 amp fuse, and like I said it had been running great since Aug. I haven't made any changes to the car or setup since I installed it. Then out of the blue on Friday, it started blowing in-line fuses. I try replacing the fuse, and as soon as the ciruit is closed, the fuse blows (car is turned off during this). I've replaced the power, ground, and remote wires, but nothing. Could my M2-ATX power supply be going? Anybody have any other ideas?

**blazinlow** · 04-01-2007, 01:32 PM

i had a similiar problem. Turned out where i made splice to lengthen the main wire from the power supply to the battery, i used a butt connector. It got wet, corroded, and broke in half and was shorting out on the floor under the carpet.

**h3rk** · 04-01-2007, 01:35 PM

Have you tried it removing the mobo (all of the load removed) connections from the M2ATX and seeing if you still blow a fuse. If it does (blow) and your inputs (Batt,ign,gnd) are good, its the P/S.

I agree with #2, lift both end connections of the batt wire and check resistance to ground

**PharmD Heel** · 04-01-2007, 01:44 PM

Thanks for the suggestion h3rk. I haven't thought/tried that yet, but will do so this afternoon. My gut feeling is it is the power supply b/c I've replaced all the power/ground/remote wires and connections (including battery connection). One thing I forgot to originally mention is this problem began when I was towing my boat. Could having the trailer lights hooked up have caused some kind of problem?

**PharmD Heel** · 04-01-2007, 04:32 PM

I solved my fuse blowing problem, but have yet to figure out exactly why they were blowing. I took the advice from above and unplugged the motherboard from the power supply then reconnected the power wire. The fuse did not blow when I did this. So I reconnected the motherboard to the power supply, conncected the power wire, and the fuse did not blow. Finally, I connected the DVD Rom and to my surprise the fuse once again did not blow.

So I no longer have fuses blowing, but I have no clue what was causing my problem to begin with. Guess I won't complain too much though seeing as how everything's working fine right now.

**h3rk** · 04-01-2007, 04:43 PM

Somethin in ur puter is pullin too many amps....sometimes. Just a guess, but I'd say HDD. As they get older they can increase is load demand.

**Memphetic** · 04-04-2007, 08:24 PM

So why would it work now if it didn't before? Curious because I'm blowing fuses left and right as we speak. All of my connections are good though.

**h3rk** · 04-04-2007, 08:41 PM

My guess is that since our "von Neumann" or "Princeton" computer architectures are wonderful multiplexed machines, what is pulling too much current is not always on, and the overall current is probably not caused by one sole offender. And not all conditions that cause currents to rise above normal levels are constant. Bearings and motors (HDD) will have different currents at different temperatures, just as one example.

**Memphetic** · 04-04-2007, 08:50 PM

so what am I gonna have to do to fix this then?

**henkbliek** · 04-04-2007, 08:53 PM

Hmm, I think mr Harvard will give just as much problems in his own way

But it certainly doesn't hurt to eliminate troubles by disconnecting them. Just make sure you have a pile of fuses ready...

You can also try a one-step larger fuse; so if you have 10amp now, try a 15amp one. If there's a shortcut then it will blow anyway. But if it's a slight overload then it will remain.