thaipokey

I am new to Mercedes and I have an ML500 2003 that I got a few months ago that had no Navigation/Radio in it. So, I ordered one, I plugged it in and the unit did not even power on. There was no hum, no electronic warmth, no Wait Screen for the code, nothing. I check the fuse on the unit and under the hood (F21), and all is golden. Contacted the guy who sold it to me and he swears he tested it before sending it to me and it worked just fine. He is now saying and I quote "there is a problem with another one of your electronic parts for the sound. I know Mercedes cars are temperamental when any of its sound components are damaged, none of it will work. Best bet is to have it diagnosed professionally by a MB tech."

Is he feeding me a load? If he is not feeding me a load, what electronic part or parts is he talking about?

DrX

The headunit should still power up even if other components are faulty.

You need to check for power at the harness. Do you have a voltmeter?

Make the sure the ignition key is turned to position 1 or 2.

thaipokey

My thinking also!!! Will give the voltmeter a try - good idea thanks. (that should read 12volts dc right?)

DrX

Is that a rhetorical question? Do you have a DVOM?

thaipokey

No, sorry if it came off reading like that, my apologies!!! Yes I have a DVOM and was just double checking on the volts that I should read at the fuse of the unit. Again sorry if my post came across as condescending or insulting in any way.

DrX

No problem. When you said you inspected the fuses, and didn't mention you had checked for power, I had to assume you didn't have a meter. Otherwise why wouldn't you have already tested the harness? And described the results?

Anyway, I've been on this forum long enough, but I still get irritated when I ask one simple question, but instead of getting a yes/no answer, I get another question back instead.

Voltage range is 11-14 V DC.