Low pitch rumble from a CDM1550 in a Camero

[arlo]

I have a new Camero with a Motorola CDM1550 with a remote trunk mount kit. The radio transmitts a low pitch rumble that changes with motor speed. A noise filter in the battery power cable did not help. The car has a plastic hood and the battery is mounted in the trunk. The 5/8 wave antenna is mounted on the rear fender on the opposite side from the radio. Any ideas?

 

[TritonBoulder47]

Camaro*


Have you checked your remote head cable...? As in the cable that runs from the radio in the truck, to the remote head in the front...? Plus check how your antenna cable is run... Make sure the antenna cable and the remote cable are not run with any electrical wires... I've seen even small guage wire cause interference...

 

[raeburn]

How does your grounding for the radio look? Are you hooked to a factory ground spot or did you "make your own" ?


Where is the power tapped from? How about the ignition sense?

 

[arlo]

Ground is a factory point in the trunk. Battery wire from radio is to battery there in trunk. There is no ign connection.

 

[108FP1]

What brand noise filter? Pondfly currently has a 30A Motorola factory noise filter for sale. It is best to stick with Motorola filters for Motorola radios.


Also, make sure your antenna cable is routed away from electrical wires, and get some of that metal wire loom to wrap your control head cable. It helps.

 

[arlo]

Noise filter is SM480-20 by Translectric. Coax runs from fender, around under rear package shelf. No coax coiled or strapped to other wires. Radio hangs under shelf. Control cable may be run under moulding under doors on driver side.

 

[SlickTop Solutions]

Does the remote head cable have a choke (torroid) on it? If not add one at the control head end and see if it helps.