Radio works but no sound from speakers
Professional
Joined: Nov 2011
Posts: 189
Likes: 0
From: Canada
Do you have a Volt-Ohm Meter (VOM)? Would allow you to make quite a few checks without pulling any panels. You could test from the connector at the radio.
They're cheap, and the $10 ones work fine. There are some features you would want for general use on a vehicle but for this problem, almost any one will do, so spend accordingly.
If you do find you need a "better" one for some job in the future, well, the $10 one won't be a waste of your $$ because it's often useful to have two or three meters going at the same time anyway.
You can use a continuity tester (aka auto test lamp), but the probe/alligator clip is not going to be that convenient; two probes from a VOM are much easier to deal with.
Find a wiring diagram of the radio circuit for your year truck online, and check the speaker leads at the radio connector. You could test all of 'em at the same time, one after the other.
If there is both + and - wires going to each speaker, set the meter to ohms, lowest scale (should probably have 10 ohms available to use, but if not just go to the next available setting that's more than 5; you want to use the lowest available one because the meter is more sensitive at the lower scales), check where the leads plug into the meter to make sure you've got the correct two (usually there are three available) and do a test:
Short (touch the + and - probes together) and check the meter ... should go from lots to zero or really close to zero, like 0.05 or something. Separate them; back to lots, touch again; close to zero. If it does, all's well and you're ready to test. If not, then the cheap meter you bought needs a battery, or you've got the probes connected to the wrong ports on the meter. Battery replacement will probably need a screwdriver, by the way. Anyway fix what's wrong, test again, should be good to go.
Put one probe on one speaker's + and the other on the -. Probe polarity isn't critical ... works both ways. If it reads a very high number there is a problem in the wiring (broken wire, connector, or unconnected at the speaker); if it reads a very low number ... close to 0.00 ... then there is a short in the wiring.
If there's only one wire going to each speaker, then put one probe on that speaker wire and the other onto a convenient ground spot. Same readings, same conclusion.
If it reads some intermediate value ... say 3 or 4 ohms ... and you hear a little noise from the speaker when you connect the probes each time (the meter uses battery power to test for impedance, measured in ohms; you'll hear the battery voltage move the speaker) then that wiring and speaker are at least capable of working, and at this point can be considered good.
Chances are at least one of the speakers has some issue with wiring, though. Run through all four in the same way and see which it is. Then you can deal with the wiring, connector at the speaker, etc for that speaker, and in most cases you'll be done.
If not, post back, we'll figure it out.
They're cheap, and the $10 ones work fine. There are some features you would want for general use on a vehicle but for this problem, almost any one will do, so spend accordingly.
If you do find you need a "better" one for some job in the future, well, the $10 one won't be a waste of your $$ because it's often useful to have two or three meters going at the same time anyway.
You can use a continuity tester (aka auto test lamp), but the probe/alligator clip is not going to be that convenient; two probes from a VOM are much easier to deal with.
Find a wiring diagram of the radio circuit for your year truck online, and check the speaker leads at the radio connector. You could test all of 'em at the same time, one after the other.
If there is both + and - wires going to each speaker, set the meter to ohms, lowest scale (should probably have 10 ohms available to use, but if not just go to the next available setting that's more than 5; you want to use the lowest available one because the meter is more sensitive at the lower scales), check where the leads plug into the meter to make sure you've got the correct two (usually there are three available) and do a test:
Short (touch the + and - probes together) and check the meter ... should go from lots to zero or really close to zero, like 0.05 or something. Separate them; back to lots, touch again; close to zero. If it does, all's well and you're ready to test. If not, then the cheap meter you bought needs a battery, or you've got the probes connected to the wrong ports on the meter. Battery replacement will probably need a screwdriver, by the way. Anyway fix what's wrong, test again, should be good to go.
Put one probe on one speaker's + and the other on the -. Probe polarity isn't critical ... works both ways. If it reads a very high number there is a problem in the wiring (broken wire, connector, or unconnected at the speaker); if it reads a very low number ... close to 0.00 ... then there is a short in the wiring.
If there's only one wire going to each speaker, then put one probe on that speaker wire and the other onto a convenient ground spot. Same readings, same conclusion.
If it reads some intermediate value ... say 3 or 4 ohms ... and you hear a little noise from the speaker when you connect the probes each time (the meter uses battery power to test for impedance, measured in ohms; you'll hear the battery voltage move the speaker) then that wiring and speaker are at least capable of working, and at this point can be considered good.
Chances are at least one of the speakers has some issue with wiring, though. Run through all four in the same way and see which it is. Then you can deal with the wiring, connector at the speaker, etc for that speaker, and in most cases you'll be done.
If not, post back, we'll figure it out.
Last edited by Johnny2Bad; Feb 9, 2012 at 05:46 AM.
A PO can have an aftermarket stereo but swap it back out for the stock unit before selling it, so it can look very stock but still have undergone some hasty wiring mods leaving you in the quiet zone. I recently installed a new head unit & all 4 speakers on my 2001 ram, now they all work. When I got it last year, only 1 rear speaker worked. Even after I installed everything, in near darkness, only 1 speaker worked. In the daylight I found that the purple & blue wires for the adapter kit look similar & I had it wrong, now it works great with all alpine speakers. Now I just need something better than the weak dual head unit or an external amp because it flakes out above volume setting 38, but that is a product issue, not a wiring issue.