400W inverter troubles!

**Justin_Noland** · 05-30-2007, 02:26 AM

I was using a Black & Decker 400W inverter, off my 12v auxiliary input, and I have burned out three of them, and popped two 20A fuses in my 98 GMC Sonoma fuse box, as well as blowing at least one or two of the 8A 250V fuses in the inverter itself, during the last month. THe problem is, while I have another generic branded 400w inverter (from Schucks), which will power my PC fine, when its on and my input on my pioneer deck is set to my auxiliary line in (from my PC), I get atrociously painful dirty noise over my speakers, rendering my PC useless for music. With the black & decker inverters, my audio is crystal clear, except for the nasty problem of them burning out after an hour or two of run time. My question then is this: I am looking for a cheap inverter that can run off of a 12v cigarette lighter/aux power over a 20A circuit, that won't give me dirty power over my stereo. I know it has something to do with the way the circuit in the inverter is built that causes this, but that is the extent of my knowledge. I am looking to pick it up some place local (from Portland OR) so like a wal-mart or home depot or something. My PC is a PIII 1000mhz, 512 RAM, humungus 7.45 gig (:P) hard drive, with a 200W PSU. I have nothing on any of my 12v or 5v rails from the PSU except for the mobo and the hdd. The LCD is a 7 inch touch panel on a ~25w power supply @ 10v. So all in all, I might be pulling down ~200W constant, with a peak around 250.

Thanks everyone for your time. If you need more info or anything please just ask, I included everything I could think of off the top of my head. I am brand new to car computers (or as my friends affectionately call it, the TruckPC). Also, I am incredibly poor, so as much as I would like a 320W DC-DC inverter from Opus Solutions, its a wee bit out of my budget.

Thanks again!

Justin

**MatrixPC** · 05-30-2007, 04:10 PM

Originally Posted by Justin_Noland

inverter that can run off of a 12v cigarette lighter/aux power over a 20A circuit

That is the source of all your problem.

Run a dedicated power source for the inverter. What is that mean is run a 8GA or 4GA wire from the battery to the inverter.
You can use a relay to switch the inverter on/off or just stretch your arm and switch it.

**billmee** · 05-31-2007, 06:28 AM

I had a similar problem until I grounded the case of the PC.
Turns out the inverter I used left the ground pin of the ac adapter floating ( disconnected ).
I pulled a wire from grounding point to a chassis screw to clean it up.

I'd say do not give up on the inverter until you try this.

By the way I used a 300 watt inverter running off the 14ga cigarette lighter wire for a couple of years with no problems.

**Justin_Noland** · 06-01-2007, 01:04 AM

thank you both for the great input. I am going to try and ground the case of the PC to my car first, and hopefully (knock on wood) save myself a couple of bucks. Otherwise, I'll just buy an inverter and tie it into my battery. Speaking of which, say I get some 8 or 4 ga wiring, how exactly would one go about connecting it to his battery and running it into the inverter in his cab. I'm a computer nerd, not a mechanic, unfortunately! :P

Thanks again for all the help!

**Justin_Noland** · 06-01-2007, 03:27 AM

Problem solved! WOOT! I used a piece of like 12 g wire and ran it from some random screw on my case to the bolt of my driver seat, and presto, my problem was solved. THANK YOU SO MUCH BILLMEE, you saved me like $70 for a new inverter, and the trouble of wiring something from my engine to my cab. YES!

**2k1Toaster** · 06-01-2007, 03:49 AM

**Justin_Noland** · 06-01-2007, 12:58 PM

I know, I know. I *do* need to run it direct to my battery, but I think I'm going to get myself a bigger inverter first. I am thinking about running some wireless gear to turn my truck into a broadband-over-cellular mobile wireless networking rig, so i'm probably going to step up to an 800w and that will *have* to be connected directly. And in regards to the picture above, is there actually potential for fire, or would blowing fuses or burning out the inverter be more likely?

**MatrixPC** · 06-01-2007, 12:59 PM

Originally Posted by Justin_Noland

Problem solved! WOOT! I used a piece of like 12 g wire and ran it from some random screw on my case to the bolt of my driver seat, and presto, my problem was solved. THANK YOU SO MUCH BILLMEE, you saved me like $70 for a new inverter, and the trouble of wiring something from my engine to my cab. YES!

It may solved the problem you have but you are playing with fire. Look at the post by 2k (above this one). It basically very popular image around here.

As to run a cable from the battery to the cabin. Well, here you go.
- Get a 4GA wire instead of 8GA because you never know when you want to add an amp or any other power hungry toys.
- You should use an inline fuse about 1ft from the battery terminal.
If your car is automatic, look around the brake booster for pre-drill holes normally cover with rubber caps/plugs. Those hole are generally for clutch master cylinder on manual car. Polk a hole with a philip head screw driver on the rubber cover and push the cable thru the that hole. If there isn't a rubber (somethign else instead), you should get a rubber goomet from hardware store and use that.
If your car is manual, you still looking around the front to see if there is any pre-drill hole. If there is one, you are in luck and use like I said above. If there isn't one, well you have to push the wire thru the main cable harness (big junk of wires from the engine bay thru cabin via big rubber seal) on your car. To do so, use a screw driver and carefully polk a hole on the main harness rubber seal and push the 4GA wire thru.

If the wire is hard to push thru, lub it. Use some vaseline and rub the wire. You can push/pull it with ease after lub.

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