After market radio turns on but no sound

QSEFERI

MEMBER
2002 HONDA ACCORD
180,000 MILES

So I bought a new radio from Walmart it is called dualcar is the brand it is a double din stereo for my car. I wired everything about ten times first it was not turning on and then magically it turned on one day and worked fine for a couple days and than started making this buzzing noise, but only when I turned on the headlights. I figured the ground wire was not connected right. So I took the thing apart and rewired everything. Now the radio has absolutely no sound I rewired everything over again still the same problem. I do not know what to do with it anymore I am very frustrated. I think it might just be the car being old because I had to switch a couple fuses in the process. At one point my whole dash board went dark I forgot to mention but that got fixed when the radio randomly turned on two days after I put it in. Please help any suggestions would be appreciated thanks!

1 Reply

CARADIODOC

MECHANIC
33,755 POSTS

How did you know which car wires were for which function? It sounds like you are using a running light wire or a dash light wire for the new radio's ground wire. Typically, original radios have a running light/tail light wire to tell the display to dim when the lights are turned on, and a dash light wire to tell the display how much to dim. Aftermarket radios do not use those wires.

When a lamp wire is used as the radio's ground wire, the radio might work intermittently by getting grounded through all the tail light bulbs, but that cannot happen when the lights are turned on. That puts twelve volts on the radio's ground wire. The radio is also grounded, (poorly) through the antenna cable. That will create a short circuit for the tail lights and cause that fuse to blow.

If the dash light wire is used as the radio's ground wire, the radio gets grounded through the multiple dash bulbs and any others on that circuit. Whether it works or not depends on where you set the dash dimmer control. Most cars by the mid 1990's used "pulse-width dimming" for their dash lights which means they turn on and off at between 400 to 15,000 times per second. The ratio of off-time to on-time is varied to adjust the brightness. If that wire is used for the radio's ground, you might hear buzzing in the speaker, but eventually the dimmer control or the radio will be damaged.

One quick test is to unplug the antenna cable. If anything changes, the radio is not grounded properly.