Cobra & truck not playing together well

[bull8042]

I keyed my mike last night and my speedometer died and the brake light and ABS light came on. After a few minutes, the speedometer started working again. After stopping and restarting the truck, the ABS was happy again. I tried keying the mike again, only to get the same results except this time I also got the check engine light. HOWEVER, after restarting the vehicle, no good! Speedometer still won't work and the dummy-lights are still on.
I have changed nothing with regards to the radio or supply power. However, I have just moved the antenna to the rear of the bed and installed a new 18' cable. I have been talking on this radio for a couple of weeks so far with no problems until today.
'99 Dodge Ram 2500 4WD, Cobra 148 GTL, 18' coax with Firering connector, 36" Firestik II.
The power is connected directly to the battery via fuse and shielded multiconductor. The shield is connected only at the battery end. My battery is a new Optima Yellow Top and I am running a 120A alternator. Nothing else is powered on this power cable.
I also have a Truspeed speedometer calibrator under the dash.
Anybody seen anything like this before?

 

[Moleculo]

Sounds like RF is getting into the computer by way of the power lines. How much power are you putting through the antenna, out of curiousity? When you say you moved it to the rear of the bed, is it in a stake pocket? Where was the antenna before you moved it?

With a short 3' antenna on the rear of the truck, my guess is that you've sort-of directed the RF right at the truck's computer or some diagnostic sensor. I would bet money that if you put a mag mount antenna on the roof of the cab, the problem would go away.

 

[bull8042]

Sounds like RF is getting into the computer by way of the power lines. How much power are you putting through the antenna, out of curiousity? When you say you moved it to the rear of the bed, is it in a stake pocket? Where was the antenna before you moved it?

With a short 3' antenna on the rear of the truck, my guess is that you've sort-of directed the RF right at the truck's computer or some diagnostic sensor. I would bet money that if you put a mag mount antenna on the roof of the cab, the problem would go away.

I am only putting out 3.5W. The antenna was moved from the front stake pocket using a ball-mount to the rear stake pocket and a stud-mount. I have verified from ground to shield that there is continuity and very low impedence as well.
Hmmm. I guess I am down to replacing the computer, then crossing my fingers and hoping that it was merely coincidence that it died at the same time I keyed the mike.
I can't find anything else wrong, and I am definitely not the first person to try and put a CB in a motorized vehicle!

 

[AMPOWER]

I have a 97 Dodge Ram 1500 4x4 ext cab w/8' bed...
The computer going out on it was just a fluke....
i run my truck as a compettition truck and still have the origional computer in it...

You have to GROUND the snot out of that truck...
-bat to frame,engine to frame..hood to body...bed to frame,
cab to bed,...etc...

Got to a muffler shop and ask them to weld a bolt onto the frame of the truck 4x on each side of the frame...
So u drill no holes in it
And you need 1'' wide ground strap...
If you need pics of how to do this..ill take pics of my truck and send them to you e-mail...
My e-mail is ampower1@hotmail.com

After its all grounded?? all your problems will go away...
And an aluminum antenna say like a Preadator 10K will work much better!!!

AM POWER

 

[bull8042]

Cool. I have a roll of bonding strap, so I will get busy.
I have a new Mopar Performance computer on it's way and looking for a new speed sensor (The stealership wants more than it is worth). I am beginning to think more that it's just the sensor crapped out, so I want to stick a new one in first, see if the speedo works then key the mike a few times. If it continues to function after that, then I will stick in the new computer and call it a job well done.
Thanks for the help guys.

 

[AMPOWER]

Or you can drive the truck out to illinois and ill do it all for you ???

 

[bull8042]

Or you can drive the truck out to illinois and ill do it all for you ???

hehehe Thanks for the offer, but I don't know if I could stand the bouncing for 14hrs.