Modified my workman pm5 mag base coax

[patrick[mi]]

from the light duty coax cable to RG8X which is 95% shielded and after I was done I had to add a 12 in stainless extension under my Chimp antenna to get the swr's back down. Then after I got that all straightened around with swr's around 1.2 when I talk through my mic I get an antenna light on my Cobra 29 radio. I'm almost to the point of putting the old cable back on the base an forgetting about the fact the when I key the mic the signal from the cable along the frame rail turns the brake light on for the trailer brake unit next to the steering wheel. Any help here would be greatly appreciated since this is all so new to me.
Thanks in advance to all that reply,
Patrick

[patrick[mi]]

Okay so today I decided that maybe it's a water issue because the mag base isn't sealed completely. First I took it back apart to verify everything is exactly as it was with the old coax and it's all peachy. Next I dried everything out with a heat gun as it rained yesterday and today and reassembled. Then I cut a round piece of thin rubber about 1/2 in larger than the plastic base itself and siliconed the rubber to the bottom so it's completely sealed and no water can get in. Next I siliconed the cable where it goes through the side of the plastic. It's sealed and no water can get in now. Check my swr's and have them pretty close to even at about 1.3. Then I jump over to channel 19 to see if I'm getting out and ask for a radio check. Sure enough my antenna light blinks with me as I talk. None of these peculiarities ever occured with the RG8U coax. So I ask again why is the better shielded RG8X coax causing all this? Does that mag base need to bleed off something in order to function properly?
I'm getting out with the signal but the antenna light issue is bugging me because I was told that the antenna light comming on means that I could burn up my radio. Granted it's a Cobra 29 Classic, but hey. LOL
Patrick