Look for some help with this one. I installed a Cobra LTB29 with Bluetooth in my JK. The antenna is a through the body mount. When I am driving and key the mic everything is fine. The problem is after I key the mic and speak into it; my wipers come on and all the lights on my instrument panel light up like have just started the JK. I have the CB wired direct to battery with the red wire to the positive post and the blk with red strip to the negative post. Anyone had or heard of this problem. Thanks in advanced.

 

That sounds like stray RF signals. Usually comes with poor grounding.

Did you tune the antenna? If so what is the SWR reading?

 

So, it sounds like it only causes interference when modulation is applied (as in, when you speak)... has this radio been "peaked and tuned" by chance? Sometimes that action can cause radios to operate poorly and cause excessive interference.

Also, I agree with what is mentioned above on both points. Grounding is frequently part of the problem for these types of issues. Tell is more about how your antenna is grounding at the antenna mount location. Perhaps post a couple pics of the antenna mount.

 

All the above comments are correct. Also, do you have your RF cable routed parallel to any other harness or along the instrument cluster? If so, moving it away from other cables and at least 5" from the cluster may do the trick. Stray RF can cause all kinds of issues.

 

^^^ good point about the coax cable being run near wiring harness. Another member had a similar issue and fixed it by re-routing his coax.

 

How is your coax feeding the antenna. You have a 'through body' mount so I'll assume you have a good ground there, a ballmount? You want that coax braid grounded close to the feedpoint, on the antenna's ground. This smells like a wonky ground, like you grounded it through the brakelight or somesuch.
It's worth saying so I'll say it again, you want the braid of the coax attached to the ground of the antenna, close to the feedpoint and without additional length.

 

This may be the problem. I installed the cb in the dash and ran the coax along driver side roll bar, then down the driver side A pillar, which runs right behind the instrument cluster.

The antenna was tuned with an SWR. Then I calibrated it with the built in SWR on the cb.

I get some pics of the mount. But I is located on the driverside rear between the taillight and tailgate.

 

I'm not sure I understand this statement. The antenna should be tuned with an external SWR meter inline between the radio and the antenna. The SWR meters in CBs don't tend to be accurate enough for tuning, they mostly serve to tell you if the SWR is WAY off.

 

That said, do get us some pics of the mount (close up on the mount)

 

Had a similar problem with my Wired HDH switch setup. Turned out to be a ground problem where the connector for the coax to the antenna connected to my mount. Although I did try and remove the paint before installing I didn't get enough removed. Caused all kinds of fun problems with the HDH setup. Once the all the paid was removed on the contact point everything was fixed and no more problems.

To check the SWR using an external meter. Remove the antenna cable from behind the CB and plug it into the correct port of your meter. The meter should come with a short cable (6" to 8") that connects from the meter to the back of the CB. The meter will come with instructions on how to calibrate then test the SWR.

Key things for tuning the Antenna.
1. Get a tunable antenna that has an adjuster and not one you cut.
2. Always put the rubber cap on for testing, testing with out it will effect the SWR so test with the cap on.
3. Try and test in an open area and not next to buildings or larger trucks etc.
4. Test SWR on upper and lower channels and tune for the channel you will use most often. Our club uses channel 4, so I tune around channel 4.

Two good webpages on SWR and Tuning
rightchannelradios.com/cb-antenna-tuning-swr-explained
rightchannelradios.com/tuning-cb-antenna-adjusting-swr

My comments are more general information as you may know much of this, but good information for others looking at the issue.