quesiton on radio CDM/amp

[Tiger Joe]

just picked up a 92 3500HD tow truck. radio doesn't work, well technically every function works, but no sounds comes out of the speakers

From what I read, this is a problem with the CDM box located above the gas pedal.

heres the question- can I buy any CDM and swap it in, or do I have to find that specific part number?

[hutcholdschool]

From my experience there are two models of those boxes. One for radios that have a equalizer/cassette player and a different one for radios that only have a cassette player. If you go on ebay and look up those amps you will find a seller that lists part numbers for the equalizer one and the one without the equalizer.

[7echo]

There is some info on our radios near the bottom of this page. They will repair your factory radio to work. I tried 2 junk yard boxes and one from a member on another forum and all were DOA. I have not used the service below but am considering that vs a new system.

http://www.carstereohelp.com/chevrolet.htm

[Tiger Joe]

well I took a chance on 2 used CDM boxes from ebay. 1 was dead. the other gives me the exact same issue I'm currently having- everything works, or appears to work, but no sound.

I found a "deal" on a complete radio- cdm box, radio, and tape deck. gonna try swapping all 3

[b454rat]

For as cheap as stereo stuff is, why not just get all new? Could get complete system for couple hundred bucks, and sound way better than the factory one.

[abig84]

my 1990 radio quit working after a few years so i went and bought a aftermarket radio to put in place of the tape deck/eq the second i unplugged the tape deck set up the radio started working. no idea why or how that worked but worth a shot.

but if you cant figure it out they do sell a kit to put a aftermarket radio in the middle of your dash, just kinda goofy having two radios though

[Tiger Joe]

Well this is a tow truck that will likely get driven very minimal. Don’t need anything fancy would rather just keep it stock.

So I bought a complete radio- head unit, equalizer box, and tape deck- plugged it all in and I get the exact same thing!

So now I’ve eliminated the radio. Both radios do the exact same thing- everything works, but no sound. Is it possible that all 4 speakers are blown at once? And I got zero sound from them?

[b454rat]

Even if blown they would crackle or make some type of noise. Need to check the connections at the speakers, then trace the wiring and see if they got cut or whatever.

[abig84]

i wanted to keep mine stock but aftermarket radios are so cheap now. just got one from walmart for $20 has usb, bluetooth, mp3 player am/fm.

something is wrong with my speakers in my truck, the rear ones are grounding out or something if i try to hook them up i get a very loud buzzing sound so i kinda wonder if it could be something like that, maybe the speaker wires are grounding out and shortening out the radios?

it could be quite possible that all the radios were junk, mine, my friends, and my old work truck's radio dont work. must have been a bad design

[Tiger Joe]

I'm guessing if its a speaker issue, its probably with the rear ones? Do they run under the sill plates on the floor? trying to figure out where I can disconnect them

[abig84]

im guessing they do? mine were disconnected and had new speaker wire hanging there when i got my truck so i figured one day i would just hook them up and they just made a insane buzzing sound. im not really much for loud music so i just left the front two hooked up and im fine with that

[Tiger Joe]

ok thanks. sorry for stupid questions but this truck is too long to fit in my garage and I only have about an hour after work (if that) to work on it outside before its too dark.


trying to make the most of my hour!

[Tiger Joe]

Well let me answer some questions in case anyone in the future looks for this

Yes both rear speakers run down the drivers side floor. Plug directly above the fuse box you can disconnect if you need

As for me- I solved my radio issue. Turns out ALL my speakers are blown. Don’t even know how it’s possible they all blew at once, but I took a chance ordered a pair of new ones. Plugged em in to the dash and bam I have a radio.