Radio Install - Help!

[residualboulders]

So I've been tinkering with a new head unit in my 55 in between other projects. I finally got all the wiring run and hooked it all up. Works great, until I start the truck. With the ignition in ACC position, everything works great, but as soon as I start the truck it's static and muffled sounds.

Any ideas? I ran power direct to the battery thinking maybe it was my power source but I get the same result. I can't see that it's a grounding issue. If it were, would it not have the same issue in ACC position or started?

 

[J Mack]

Crackling/ ticking noise or whining sound.

Things to look at, grounds, capacitors on ignition and alternator, plugs and wires, grounds grounds and grounds.

 

[residualboulders]

I'd say more of a muffled crackling ticking noise than a whine.

 

[thebus]

during FM or AM? still sounds like grounds.. are the speakers rated to the new amp from the head unit? im not really an audiophile i do i like pictures though!

 

[residualboulders]

its in am/fm, bluetooth or USB. Same issue. If it were a grounding issue, wouldn't it react the same in ACC position? I've tried disconnecting the sub. Starting to wonder if it has something to do with the ignition switch.

I don't have a pic of the wiring with me, but here is one of my 40.

 

[J Mack]

If it were a grounding issue, wouldn't it react the same in ACC position?

Web forum electric diagnosis is difficult on its best day but I’ll give it a shot.

I understood your issue to be radio frequency interference (RFI) or electrical "noise" and it’s often caused by ignition systems, alternators, wiper motors, etc.,so technically “engine or motor” noise.

Grounds suck on pigs and faulty grounds will cause similar issues to the ones you describe, your antenna should have a good chassis ground so the shielding in the wire can do its job, radio should have a good independent ground (separate from any other accessories especially motors) again so the shielding can do its job, engine and body grounds suffer from neglect and everything is better when they are maintained, it would be a good time to check a common ground battery/engine/frame/body.

Your ignition system is inherently noisy (radio interference) and several things can make this better or worse, the capacitors on the coil and or distributor are cheap and easy to replace, resistor spark plugs and wires are used to reduce noise and if the they are in need of replacement often times you’ll hear a “muffled crackling ticking noise” in your radio.

If I misunderstood you and nothing is running and no other changes other than simply moving your key from off to ACC position creates the noise then I would say you’ve crossed some wires when you installed your radio.

 

[residualboulders]

Thanks, I'll double check what you have mentioned above. The sounds is so suppressed when ignition is turned on I think it has to be something more than frequency interference. I'll double check my wiring again and these other items you mentioned.

thanks!

 

[J Mack]

I think it has to be something more than frequency interference

At the end of the day that’s the only thing your radio amplifies so you’ll need to isolate the unwanted frequencies one way or the other.



BTW, we are going to lose the sty if you don’t post more pictures. They have no tolerance for all these words without pictures..

 

[residualboulders]

You're right. More pictures can't hurt. Here is another, lakeside the day after I bought my 55.

 

[residualboulders]

Figured it out. I'm not sure why it was only happening when the truck was running, but there was a bad connection headed back to the rear speakers which I haven't installed yet. Once I replaced that, it seems to work great.

I appreciate the feedback here. Here is a picture to make this thread more interesting. Sometimes I miss my HJ45.