Chrysler Repair: 1994 Dodge Ran Van Radio Grounding Issue, sheet metal screw, dodge ram van

Question
Hi Roland,

I'm trying to install an aftermarket radio into a 1994 Dodge Ram Van 2500 class. I have the radio out, and an aftermarket set of 2 clip on harnesses to attach to my new radio. My problems are:

a) I can't find the ground wire anywhere, or anywhere it would have connected to the old radio. There is grounding wire on my new radio's harness, but no ground wire in the vehicle.

b) There are no rear speakers in the van at present, but I want to install them. Can I connect the new rear speaker wires directly to the new radio's factory harness?

Answer
Hi Paul,
In the '90s and earlier most Chrysler radio installations did not have a separate ground "wire" in the common meaning of that term (an insulated black wire as part of the harness). Rather it uses a braided copper strap that is attached to a threaded stud on the radio chassis with the other end of the strap is bolted to a metal bracket nearby, usually the instrument panel upright support. Such a strap is a more reliable and "quiet" ground than a simple wire. If you removed the original radio you may have disconnected the grounding strap without recognizing its purpose. If not, then look for such a strap to be hanging freely at the rear area or the radio opening. In any case you can ground you new radio with a jumper from its ground wire to a clean metal surface nearby, using a sheet metal screw to hold it firmly.
As for speaker wiring, you need to read the manual for the new unit to see how many speakers there are provision for, and what impedence the speaker coils should have in order to match the outputs of the amplifier (assuming there is an amplifier as part of the new unit). Use care to observe the polarity of the speakers with the polarity of the audio output wires of the unit so that the speaker cones all move in the same direction and thus to avoid cancellation of low frequency (bass) sound.  If the unit doesn't have include an amp you will need to get such a unit to power the speakers. If that were the case it would be noted in the instructions, no doubt.
Roland