Are the factory cross rails grounded?

LibertyCRD · **Posted:** Fri Apr 21, 2006 9:17 am

I'm thinking of mounting my CB antenna to the factory side rails on my KJ. But I need to know if the factory rails are grounded somehow or not. Does anybody know if the side rails are grounded? Or will I have to run a separate ground wire from the mount to some location on the KJ?

pixeldzn · **Posted:** Fri Apr 21, 2006 9:25 am

LibertyCRD wrote:

I'm thinking of mounting my CB antenna to the factory side rails on my KJ. But I need to know if the factory rails are grounded somehow or not. Does anybody know if the side rails are grounded? Or will I have to run a separate ground wire from the mount to some location on the KJ?

They aren't intentionally grounded I would bet, but maybe by design. Not sure how you check that.

Se7enLC · **Posted:** Fri Apr 21, 2006 9:35 am

LibertyCRD wrote:

I'm thinking of mounting my CB antenna to the factory side rails on my KJ. But I need to know if the factory rails are grounded somehow or not. Does anybody know if the side rails are grounded? Or will I have to run a separate ground wire from the mount to some location on the KJ?

I believe that the rail itself is not grounded, but inside the front plastic part there is a screw that is grounded that you can attach to. Look for roof-mount light installs and you'll see a few people using that point to ground to.

If you have a multimeter it's very easy to test for a ground. If you don't have one, aim for the discount rack at an auto-parts store, you can probably pick up an auto voltage tester for like $3 (it's just a test for 12V and has a light that lights up. It will only detect a 12V difference if it is relative to ground $1.99 online)

How to Test for a Ground using a Multimeter / Voltmeter:
(note: this doesn't test how GOOD the ground is, just that it is a ground)

Set multimeter to measure DC voltage (will be a V with a horizontal line over it, most likely)
Touch the red lead to a positive voltage (battery terminal, cigarette lighter, etc). Be careful not to touch it to ground as well, you'll blow a fuse and be embarassed. Might even cause damage or injury. Just be careful where you clip it. It's best to use an alligator clip on a hot wire that is nowhere near anything metal.
Touch the other lead to anything else toy think might be a ground. If the meter reads 12-15v or so (typically 13.5 or so) it's a ground! If the meter reads nearly zero, it's not a ground. Simple!

Of course, I take no responsibility if you blow yourself or your jeep up; just cuz I'm an electrical engineer doesn't mean that I didn't mis-type something or miss something stupid. This is how I tested for a ground for my CB ~a week ago, though. Correct anything I'm missing or add to it, if you can.

LibertyCRD · **Posted:** Fri Apr 21, 2006 10:00 am

How do you get that front plastic piece of the side rails off? Do they just unsnap?

Se7enLC · **Posted:** Fri Apr 21, 2006 10:42 am

LibertyCRD wrote:

How do you get that front plastic piece of the side rails off? Do they just unsnap?

I haven't personally done it, but here's a thread on jeepkj that describes it and has some FSM images:

http://www.jeepkj.com/forums/viewtopic.php?t=2695&highlight=remove+rail

billforde · **Posted:** Fri Apr 21, 2006 10:43 am

I prefer to test for ground by using the Ohm (resistance) setting on the multimeter. Attach one lead to a know ground point and the other to the point your trying to test. A reading of 0 means good ground point. Less chance of shorting by checking voltage.

Se7enLC · **Posted:** Fri Apr 21, 2006 10:51 am

billforde wrote:

I prefer to test for ground by using the Ohm (resistance) setting on the multimeter. Attach one lead to a know ground point and the other to the point your trying to test. A reading of 0 means good ground point. Less chance of shorting by checking voltage.

Good suggestion. I was going to add that for testing how good a ground is, but I was worried that the size of the jeep would cause some weird resistance measurements (and I hadn't done it). Plus, you have to know that you have a good ground first, otherwise all you discover is that they are connected together, not that they are connected to an electrical ground (although I suppose if you use the negative battery terminal you would know for sure that it's a good ground ref)

billforde · **Posted:** Fri Apr 21, 2006 11:02 am

If you have the service manuals, it list good ground points.

Se7enLC · **Posted:** Fri Apr 21, 2006 11:04 am

billforde wrote:

If you have the service manuals, it list good ground points.

Do you know what section? I didn't even think to look there when I was searching for ground points...

billforde · **Posted:** Fri Apr 21, 2006 11:18 am

Under wiring, there is a section 8W-91 Connector/Ground/Slice Location. You will find detail diagrams there.

LoganSix · **Posted:** Fri Apr 21, 2006 1:46 pm

Grounded, I don't know. But here's my story.

I bought CD from Radio shack, mounted it under my seat and grounded it to the seat frame. Bought a add a fuse to power it from the fuse box. Upgraded the magnetic attena I used to use with a FireStik antenna/
I bought a three foot antenna with cable that included a fire ring and attached it to and adjustable elbow. I attached a flat piece of metal (got it at Lowe's) to the cross bar and mounted the fire ring and elbow on the metal.

Worked like a charm. Unfortunately the elbow didn't come with a spring like it was supposed to, so after a few low branches, the elbow piece broke off and my antenna with it. The antenna is still good. The best part, the fire ring was still attached to the bottom part of the elbow and the metal stand I created and I still get great reception.

I have a '04 Renegade with the tupperware, so the cross bar isn't touching the roof bars directly.

Antenna
http://www.westcoastmall.net/shop/product_info.php?products_id=216

Cable with Fire Ring
http://www.westcoastmall.net/shop/product_info.php?products_id=262

Elbow adapter
http://www.westcoastmall.net/shop/product_info.php?products_id=284[/url]

m0th · **Posted:** Fri Apr 21, 2006 8:20 pm

I've just installed my CB antenna on my rack. The front mount just snaps apart, it's held in place by a couple of N shaped clips. Inside is a screw that is grounded.

Take a look at this thread on JeepKJ.com for ideas:

http://www.jeepkj.com/forums/viewtopic.php?t=454

LibertyCRD · **Posted:** Mon Apr 24, 2006 7:22 am

Cool. Thanks for the link.

Are the factory cross rails grounded?

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