190E Weird problem - stereo won't turn on?

[rickdeaconx]

Hey all,

I recently picked up a 93 190E 2.6 Sportline in good shape for cheap.

The first thing it needed outside of brakes was a new radio - the aftermarket Sony that was in it was a bit flaky and had no aux port.

So I bought a cheap one off Amazon and went to install it. Immediately noticed the PO didn't install it with a harness but still no big deal, I have installed probably 25 stereos in my life.

The issue I've run into is the cheap one didn't power on. I assumed it was because it was cheap so I tried a known good Pioneer - also didn't power on.

I've checked all the wiring and I used a multimeter to test all the power - ground is good, switched is good, constant is good. All test just fine but the radio will NOT turn on or get power.

I assumed it was a ground issue but I don't see a good location to relocate the ground to - I tested it on a few spots just to see if it power (holding it to the potential ground) and nothing. I also checked the fuses just to be sure - good to go.

The weird thing is that the Sony that was in it worked - it powered on and played music, etc... so what would stop TWO other HUs from working if the prior did work?

Open to suggestions.

Thanks!

[optimusprime]

I would think your doing this with the key on,thats if you know about them . Is everything else working in the car ?.If you have 12 volts and earth ,only other thing is- fuse inside the radio itself you may need to open it up to find it . With a wire and a battery try it out again ..

[Diseasel300]

Use a 12V light bulb and make sure that your power and ground are actually good solid connections that can handle current. You can be fooled by using a multimeter, sometimes you can read voltage, but the circuit is faulty enough that it can't pass current. A light bulb will light if the circuit is good, but won't if it's bad since it draws a fair bit of current.

Also worth checking is the fuses themselves. If they're the aluminum type, hit the trash with them and install the modern brass or copper replacements. The aluminum style are notorious for developing fractures and failing at inopportune times.

[rickdeaconx]

Originally Posted by Diseasel300

Use a 12V light bulb and make sure that your power and ground are actually good solid connections that can handle current. You can be fooled by using a multimeter, sometimes you can read voltage, but the circuit is faulty enough that it can't pass current. A light bulb will light if the circuit is good, but won't if it's bad since it draws a fair bit of current.

Also worth checking is the fuses themselves. If they're the aluminum type, hit the trash with them and install the modern brass or copper replacements. The aluminum style are notorious for developing fractures and failing at inopportune times.

Thanks!

After using a light on the 12v constant, it doesn't light up. Still shows power on the multimeter.

It's possible its a fuse still, even if it isn't blown right?

[97 SL320]

The display does not light up or no sound from speakers?

This car might have a separate amp in the trunk.

Make sure your ground is an actual ground not to a piece of metal in the dash that is electrically floating. ( insulated )

You could always jumper the radio power feeds to a single wire and to the battery for a test. ( be sure to have a fuse / breaker in the line )