Car Stereos: no power to head unit, cigarette lighter, stock radio

Question
hi i have a 1984 eldorado w/ 4.1 i bought a jensen vm9212n from the guy, an he showed me it worked an all. i take it home an install with the mount, wire connecters i bought from walmart. seemed easier than other radios i did in the past. got all the wires in but wont come on at ALL. i checked red for ign. power i checked yellow for constant an checked radio fuse as well stil no power. only thing that differs from the other radios in the past for me is the radio harness for the radio does not have a yellow wire for constant power. but on the radio back with list of wires says it should have one. im dayzed an confused. please help. thanx in advance.

Answer
Hi,

I can tell you that the new head unit definitely should have a yellow wire, and it won't work without that connection.  The yellow wire is the main power connection.  If it's missing from the Jensen plug, you'll probably need a replacement plug before you can get the unit working.

I wasn't quite clear whether your yellow wire was missing from the Jensen wire plug, or from the factory radio plug.  It wouldn't be unusual for the stock radio in a 1984 to be missing a constant power connection.  This is only needed if the radio has a clock or digital tuner, which wasn't always found on a factory radio in the 80's.  If the Jensen plug has a yellow wire, but the factory radio plug doesn't have a constant power wire, then you just have to connect the head unit's yellow wire to a different power source.  The orange wire at the cigarette lighter would work, or you might have power tap points available at the fuse box.

Hope this helps!

Brian