Turn Signal Troubleshooting

1983 Plymouth Scamp GT

Fuse #16 blows as soon as key is in ON position.
This is the fuse for turn signals, hazards, tachometer, anti-diesel relay, and electronic spark advance module

I have checked for continuity in the connector, with the test between #10 and #9, and #10 and #8 giving a reading on the meter. These wires are #10 stop lamp, #8 left rear turn signal, #9 right rear turn signal. One reading is an order of magnitude larger than the other.

I have traced the wires from there to the turn signal switch with no shorts or loose connections. I have traced the wires from the wedge block to the bulkhead with no shorts or loose connections.

What's next? I need to drive out of state for work this week...

My manual says simply to test for continuity, but not what to do if there is a reading.
I'm assuming it's the turn signal switch, which look to run between $15-$30 online. Never taken apart a steering wheel before, and looks like a pretty invasive job, with special tools needed.

Is there any way to pinpoint what the problem is, particularly isolating a potentially faulty switch, without removing the steering wheel?
Some kind of rocker switch (like a moped) I can wire up somehow?

Pull off the connectors for everything but the bulbs and see if it still blows a fuse. If it does, you've almost certainly got a short in the wiring somewhere. If it were the switch it would most likely just cause high resistance and a fire in the column IMO. If it doesn't blow the fuse with the other crap disconnected then it's probably one of those items pulling too many amps.

My money's on a short somewhere.

When you say pull the connectors for everything but the bulbs, do you mean yank all but turn signal connector from the wedge block? Or pull wires from the turn signal connector

I would unplug anything that isn't for the turn signal bulbs at the connection for the actual spark control and anti-diesel relay mainly. Just get it so you're down to the bulbs. Those won't pull enough amps to blow a fuse so you'll know that it's a short with a high probability.