Grounding Explorer Sport Trac

**ChilliPepper** · 04-10-2005, 10:22 PM

Hey all.

I'm about to start installing my carPC in my sport trac and was wondering where to ground the PSU (and an AMP) that will be installed in the back of the cab. For those who know the Sport Trac interior, the body seems to be something other than metal. I thought I read somewhere that is some composite material supposedly as strong as metal but 'not' metal. There are screws that bolt the body down, but do those screws go down to a metal surface underneath?

I'm really not sure. All I know is the screws are metal and the body material seems to be fiberglass. Is there a good location at the back of the cab that can be grounded to or should I run a wire to the front?

(side note: I know I could just run the wire to the front but I read a thread that said keep the grounding wires as short as possible)

Thanks!

**dave2** · 04-10-2005, 10:42 PM

You will have to connect into a ground circuit on that car, if it really isn't grounded to the chassis. Usually the frame will be grounded, and you could just run a wire to that, but for something as small as a car pc you should be able to get away with running a small wire for ground, right along with your power wire. 10 GA should be fine. Then ground it to the battery. Look under your hood, is the negative terminal of the battery grounded to the body ? The best way to tell if your ground is ok is to use a multimeter and check the resistance from where you want to ground to the negative terminal of the battery. If there isn't a VERY low amount of resistance, don't use it.

Dave

**ChilliPepper** · 04-10-2005, 11:18 PM

Ok! Thanks for the info Dave. I will do that and just run the ground along with the power from the battery.

One other thing. I was going to use 12 gauge wire. You mentioned 10. Is there a significant difference? If so I'll pick up some 10.

Thanks again.

**pech445** · 04-11-2005, 02:18 PM

remove paint around the spot your grounding, sometimes it will not coduct if paint is not removed

**skidogg77** · 04-11-2005, 02:34 PM

Chilli,

I have a Sport Trac as well with a bunch of electronics in it, and building a PC to go in next. Good grounding points are the bolts that hold down the legs of the rear seats, the 2 brass looking bolts on either side of the center baby seat tie down on the rear wall.

**ChilliPepper** · 04-11-2005, 09:51 PM

Pech/Skid,

Thanks for the help! I'll go with the seat bolts. That's very close to where the PC will be installed, making the run the shortest.

Appreciate all the help guys,

Chilli

**dave2** · 04-12-2005, 04:16 AM

Grounding to seat bolts is generally not acceptable. They are often insulated from the chassis, and you can end up with a spotty ground because of the goop they put on the bolts to hold them in place and avoid vibrations. If the seat bolts show a good ground, or if that panel of the floor is connected acceptably to ground, check it, drill and remove the paint, then bolt your ground directly to a clean part of the metal.

Dave

**dave2** · 04-12-2005, 04:18 AM

PS I would generally not use anything less than 14 GA for a power application. I just reccomended 10 in case you had NOT bought anything. Since you have, go ahead and use it.

**ChilliPepper** · 04-12-2005, 10:46 AM

Thanks for the clarification on the gauge Dave.

I'm not sure if drilling a new hole will work. Honestly, I don't think the floor of the Sport Trac is metal. It's some other material.

I was hoping the seats, based on Skid's post, were bolted all the way down to the metal undercarriage.

I'll test it though. Sounds like Skid is successfully using it as a ground on his ST, so if the multimeter shows it to be a good ground, I'll try it out.

But I see your point, though. Will have to test and see what it looks like in my ST.

Thanks again Dave.