Radio install problem

So I am hoping someone may be able to help with this one. I've installed aftermarket stereos before in my previous car and in my truck but my truck is the only one that stumps me. Basically it had kenwood speakers in it before, only one worked and I got a good deal on some other ones that I figured I could use to replace them. Well I installed them and my passenger door speaker still didn't work after changing the speakers. I tested the same speakers on the back speakers (I have a set of 6x9"s behind my bench seat because its a single cab truck). The same speaker works on the back connection but not the passenger door wiring, maybe a bad body ground? and this is also using two different stereos. I had a JVC in my crown victoria that worked fine when pulled and put it in my truck and nothing on the right side, I pulled a cassette stereo from another 86' at the junkyard and still nothing, now my driver side works barely, however I think that one is due to not having window seals and water got in and ruined that one. Any help will always be appreciated!

Getting continuity on the speaker wires from the speaker to the head unit connector?

How much, if any, of the speaker wiring is factory vs aftermarket?

Yes, Scott/kramttocs has good questions.  And I'll bet there is no continuity in one of the wires going to that speaker.

I usually use a D cell across the speaker wires at the radio - with the wires disconnected from the radio.  That's enough juice to cause a good pop in the speaker, but not enough to hurt the speaker.  So if you don't hear a pop you don't have a circuit.

It does sound like the wires going to that location has a problem.

Are you using the factory wires to that location?

Are the factory connections being used?

I ran new speaker wired to all my speakers in all my bullnoses. Made quite a difference.

One of the first things I did to my truck before I got it running was wiring up speakers. I went to Walmart and got brand new speaker wire (blue jacketed if that makes a difference) and bought brand new aftermarket plugs and used brand new connectors.

Check your wires, has to be bad wireing.  If the speaker works on the bench, and in other locations in the truck, it is definately a bad wire

Well here’s another thing that gets me is that I changed the wire with some 16g wire I had left over just the standard red/black and still nothing.

Maybe you should try swapping left-right or front-rear channels and see if the dead speaker changes too?
(though, I don't know how you wired it)

If the output for right front has broken loose internal to the head unit you have to send it for repair or open it up and do it yourself.