Fuel Pump screwing up my CB reception. - JK-Forum.com - The Ultimate Jeep JK Wrangler Bulletin Board

dmhines · 11-02-2009, 05:34 PM

With engine off reception is nice and clean. When I turn key to start I get a couple of seconds of interference. With engine running it's constant interference. I figure it must be the fuel pump.

I'm thinking of getting some ground straps and grounding battery to body and frame to exhaust.

I also found this thread about making an RF blocker for the fuel pump:

http://97vette.com/sporttrac/rfi_fix/rfi_fix.html

I have my antenna grounded to bolt holding subwoofer in just like Cooltech instructions say.

Any other suggestions?

JKGuy · 11-02-2009, 08:03 PM

You might find it easier to just re-route the coax. Sometimes all it takes is moving it a little bit to solve the problem. I ran mine from the right rear bumper to the roll bar and then forward. I can hear a tiny bit of engine noise if I dump the squelch but thats about all.

My power is also run from the battery to the radio with a torrid coil on the power line under the dash.

dmhines · 11-02-2009, 08:09 PM

My Coax is also routed up and across the right side roll bar.

I ordered another coax that looks more shielded than the thing black firestik Coax with the firering. I'll play around with the routing of the new coax and see if it makes a difference. I need to go to Fry's tomorrow and see if I can pick up ferrite rings and redo my power. I do have i connected directly to the battery.

I do notice that if I actually hold onto the top of the antenna with my hand that all interference goes away ... wonder what that means? It is a Firestick II.

Thanks ... Dan

GoodysGotaCuda · 11-02-2009, 08:11 PM

You touching the antenna throws the whole system pretty haywire. Doesn't really do anything towards diagnosing the problem. Make sure the radio has a strong ground, as well as the antenna/mount. Grounding is the most common cause for RFI.

JKGuy · 11-02-2009, 08:17 PM

Sounds like maybe the antenna mount isn't grounded well. If you are using a spare tire mount then it's important to scrap the powder coat away on the bottom of the mount to ensure it's grounding.

I have an XHD rear bumper and just got tired of messing with it so I mounted a ball mount on the top of the bumper (serious ground) and ran the coax through into the tub and up the roll bar. I've never been too convinced of those spare tire mounts.

dmhines · 11-02-2009, 08:21 PM

Quote:

Originally Posted by JKGuy

Sounds like maybe the antenna mount isn't grounded well. If you are using a spare tire mount then it's important to scrap the powder coat away on the bottom of the mount to ensure it's grounding.

I have an XHD rear bumper and just got tired of messing with it so I mounted a ball mount on the top of the bumper (serious ground) and ran the coax through into the tub and up the roll bar. I've never been too convinced of those spare tire mounts.

I'm using the COOLTECH stainless gate mount. I ran the ground wire to the SubWoofer bolt as per the instructions.

I'll have to play around some more with the ground. I'll run a temp ground from the antenna ground directly to the frame and see if it makes a difference.

donnie · 11-03-2009, 09:19 AM

FWIW, Im using the CoolTek tail light mount and routed the coax under the carpet on the left side to the cb.
So far, I havent noticed any interference other than the normal stuff with the cb.

JdTms11 · 11-03-2009, 10:46 AM

where is your CB grounded to. i had mine grounded to the firewall and was having allot of interference issues, guy and a CB shop told me to just go directly to the battery and that along with a strong chassis ground for the antenna mount eliminated all of the feedback i was getting.

dmhines · 11-03-2009, 11:42 AM

My Cooltech is the gate mount so running it up the left side would not be an option with 18' coax.

My antenna ground is to the body ... not the frame. I'm gonna play around with better ground solutions as well and see how it works out.

Thanks all ..... Dan

whpony96 · 11-03-2009, 02:37 PM

Quote:

Originally Posted by dmhines

I'm using the COOLTECH stainless gate mount. I ran the ground wire to the SubWoofer bolt as per the instructions.

I'll have to play around some more with the ground. I'll run a temp ground from the antenna ground directly to the frame and see if it makes a difference.

You need to grind off the paint around the bolt that holds the subwoofer on or you will not get a good ground!