[Oklahoma Wolf]

If the rear woofers are working, the door woofers should be too. You have four amplifiers bolted to each of the rear speakers and door speakers. These are booster amps that work with the incoming speaker level signal from the deck. As you found, you do need to have the power antenna wire getting 12 volts to get the amp relay to turn on. You also need to have the solo wire with the female spade terminal that was back there grounded to something... that's probably the one you're referring to.

At any rate, the power antenna wire is the amp relay coil positive, and the solo wire is the negative.

It's possible (even probable) that the door speaker amps have failed. They're susceptible to bad solder joints, and getting slammed in the doors for years doesn't help them any. The amps can be repaired, but they're usually full of potting compound that's hard to deal with. My advice would be to find a 1996-1997 van with Infinity to get door speakers from - they'll interchange and you'll have a better chance of finding them working due to their position in the 3rd gen doors. Sometime in G3 they went to a different setup with the Infinity system that uses different incompatible connectors that you will have to watch out for. I believe that was in 1998-99. Just look for ones with the 4 pin connector and they should be plug and play.

 

[Oklahoma Wolf]

First, I would check the two outer pins on each door speaker connector for 12 volts (wire colors on the speaker end will be red and gray). If you have power but the speaker's not working, the amp's either dead or not getting a signal on the inner two wires.

Indeed, the door speakers are fed using the front channel head unit outputs.

No clue about jumpers... this is the first I'm hearing about it. The only single female connector behind the radio you should have is the ground for the amp relay coil. As mentioned, that should be grounded. If it wasn't before, it could be someone in the past added Infinity and messed around with the wiring. In that case, you'll need to figure out what they did first.