Help With Fuses

**silv3rman** · 04-30-2006, 01:49 PM

I just began testing my CarPC with my M2-ATX and the first time nothing happened. The second time my 20A fuse blew. I have a 60A fuse right next to the battery and a 20A right before the PC. The M2-ATX has a 15A fuse inside of it so I thought that 20 wouldve been sufficient. Currently, there is just the HDD, USB GPS and the Xenarc Touchscreen USB connected. If I were to put in the 60A Fuse where the 20A was, just so I could test it, could that possibly be devastating? I dont want to ruin anything but Im still in the testing stages and I just want to make sure it turns on/off correctly etc.

**Gearhead61** · 05-06-2006, 02:55 PM

It might be too late for this, but I've been told to NEVER put a higher amp fuse anywhere than the fuse that is already there. If you are blowing that fuse, something is WRONG, it's not your fuse.

**bunter** · 05-06-2006, 03:08 PM

You DO NOT want to do that!! Check that none of your supply voltage is being grounded somewhere by mistake or you haven't sliced through one either

**nameeri** · 05-07-2006, 03:28 AM

Strange...if it was a problem with the M1, you woulda thought the 15A would have gone first. But yeah, I would double check the actual lines going to the M1, sounds like you have a ground somewhere. Never put a fuse in there which is rated higher than the wires you have suppliying them. If you do, the wires will burn and could catch fire!!

**silv3rman** · 05-07-2006, 02:33 PM

Thanks for the reply guys. The wire that is running from the battery is 60A, it came with the 4gauge wire.

My setup is like this:

Battery -> 60A fuse -> Fuse Distro - 20A fuse - Subwoofer
|_ 30A fuse? - M2-ATX

The subwoofer runs fine. The M2 is grounded at the same point the subwoofer is. Maybe there is a problem with the M2 wire. Im not going to try to run the PC again until I figure this out because last time it blew both fuses (60A and the 30A). Im going to go check the ground wiring now. For reference im using 10gauge wire for the grounds on both the M2 and the Sub, two seperate wires to the same ground point.

**ramy_zohair** · 05-08-2006, 12:57 AM

Originally Posted by silv3rman

Thanks for the reply guys. The wire that is running from the battery is 60A, it came with the 4gauge wire.

My setup is like this:

Battery -> 60A fuse -> Fuse Distro - 20A fuse - Subwoofer
|_ 30A fuse? - M2-ATX

The subwoofer runs fine. The M2 is grounded at the same point the subwoofer is. Maybe there is a problem with the M2 wire. Im not going to try to run the PC again until I figure this out because last time it blew both fuses (60A and the 30A). Im going to go check the ground wiring now. For reference im using 10gauge wire for the grounds on both the M2 and the Sub, two seperate wires to the same ground point.

I had the same problem, turns out that the power wire from the Distr. Blk to the M2 was shorted to the PC chassis (Ground).

If the fuse on your DB blows then the problem is somewhere between the DB & The M2. If the fuse on the M2 blows then the problem is between the M2 & the PC (though this is rare cuz i guess the M2 has some kind of voltage protection - which shuts it down before blowing the fuse).

Good Luck

**silv3rman** · 05-08-2006, 06:24 PM

Hmm. Thanks ramy_zohair. In my distro block, I lost the little pin you screw in to clamp down the wire. Instead, I used a screw. I figured it was conductive so why not. Ill have to try switching it with the pin that is used on my amp's fuse and see how that works.

**silv3rman** · 05-08-2006, 07:33 PM

Alright. It turns out originally the 15A fuse in the M2-ATX blew (WTF)... Any ideas?

**silv3rman** · 05-08-2006, 07:49 PM

Could it be that the ground is too long? My amp is running at 230W and the ground is the same length. The only difference in the wiring is that the wire going from the DB to the amp is thicker. Im not sure about the amperage aspect.

**Wiredwrx** · 05-08-2006, 08:23 PM

Originally Posted by silv3rman

Could it be that the ground is too long? My amp is running at 230W and the ground is the same length. The only difference in the wiring is that the wire going from the DB to the amp is thicker. Im not sure about the amperage aspect.

I would disconnect the AMP, M2, and any other devices from the power wires. Then I would disconnect the wire from the battery hot side. Then, ehck for continuity between the positive wire and ground.

Fuses blow for 1 reason, because the amperage is exceeded. The ways for that to happen is drawing too many amps (that should not be the case) and a short of the positive to ground.

If there is no continuity, then I would check to see that all the circuit boards are not accidentally touching ground. Check the M2. How is it mounted, and to what. Is a solder point touching metal such as a metal case or metal screw that is grounded.

Check the wires, especially where it enters the car through the fire wall, to see if perhaps something sharp has cut the insualtion and is now grounding.

Otherwise, I would run some wire directly to the battery and to the M2 and the amp with out running it through the car, (just jury rig it from the battery to the trunk on the outside of the car) and see if the fuses pop.

Good luck.

Michael