VGA Cable causing engine noise

**sq_geek** · 08-15-2004, 08:35 PM

So I finally troubleshot my noise (cross between white noise and alternator whine) to be the VGA cable.

I have a 25' VGA cable (although I wish it was 15' now because I've got tons of extra wire and it's a little fuzzy) running from my dash to my trunk.

What's strange, though, is that I have the VGA cable running with the keyboard (PS2) and USB cable. Neither of them cause the noise - it's only when the VGA cable is plugged in, so it is getting interference somehow..

I'm wondering if it's because my LCD is grounded to a different spot (12v cigarette lighter for now) or if it is just getting some disturbance from any of the 10+ wires it goes near which run inside my dash, down into my kick panel, and down through the door sill to power other components of my car, such as taillights, trunk release, brake lights, fuel pump, and other various rearward car components...

Which do you guys think (as a point to begin troubleshooting further)??

I guess I could unplug my LCD power source and see if that makes a difference.. maybe it IS because of a ground loop? (does that make a ground loop?)

**paradox** · 08-15-2004, 11:17 PM

well vga cables are shielded but not a lot. cause they dont really need to be. u can wrap the entire cor din a few layers of electrical tape

or have the vga running else where

since u have SO much extra i'd recomend running it over the door instead of under.. (if u have the room) this should help.. then around your wires/HU i'd wrap it in some electrical tape

also kb/mouse doesnt carry much of a current so it wouldnt do squat

hope i helped?

**zijester** · 08-15-2004, 11:36 PM

Dont think its your vga cable. I thought it was mine too but ordered a triple shielded and didnt do a thing. Its a ground thats causing the problem. Funny thing is, this only started when I put my opus in. Didnt do it when I had my old 250w dc-dc atx. I have to track this down somewhere.

**sq_geek** · 08-16-2004, 12:23 AM

Yeah I'm not sure if it's my VGA or the fact that my VGA is grounding my PC chassis to the LCD (VGA cables have ground wires, right?) which is grounded to a separate spot than my PC is grounded too -- causing a ground loop. (Or am I on crack?)

One option would probably be to put in a ground-loop isolator on my RCA to my AMP from the PC. I think that would help... I hope it would.. It fuggin better!

I don't know what paradox means by running the VGA "over the door". How is this possible? You mean up in the roof? I don't think my car has a molding up there all the way across, but I'll double-check.. I suppose I could pop the headliner off and run it behind that, if there's room, but now we're talking some serious work and something I've never messed with before (headliner).

**sq_geek** · 08-19-2004, 11:28 PM

Anyone know how to ground a VGA cable?

Also, should I gound my PC chassis or would it not make a difference? I'll try it, I just don't want to blow something up - ya know?

I was thinking since my motherboard and vga controller and etc are not even grounded to the chassis case, I don't see how it would make a difference at all.. or is maybe the motherboard grounded by the mounting screws??

*shrug*

**SuzukiAerio** · 12-06-2004, 05:45 PM

yeah.. im getting horrible flicker on my LCD too . But i cant even begin to know where the noise might be coming from

....I do have alot of extra VGA cable too (maybe i should measured my car first)

....does anyone have any clue? or solution

**egeekial** · 12-06-2004, 06:06 PM

Try this thread... I'm not sure if it's what you're talking about or not.

Possible solution for people with screen interference (Pics)

**Cris** · 12-06-2004, 06:11 PM

You said you're running you VGA with the USB. If the USB is unplugged, is the noise still there?

**SuzukiAerio** · 12-06-2004, 08:07 PM

Originally Posted by egeekial

Try this thread... I'm not sure if it's what you're talking about or not.

Possible solution for people with screen interference (Pics)

YES!

I think that is exactly what I need to solve my problem!! Ill pick one up tommorrow

**MatrixPC** · 12-07-2004, 01:21 PM

If you suspect that RCA cable is the cause of noise, make your own RCA cable using the cheap CAT 5 cable. Each wire of the twisted pair for each + and -.