Voltage drop at ballast resistor

Paladin06 said
* Note current flow through Ammeter. Should be around 5 amps discharging (3-4 to alternator field, 1-2 to coil and ECU). (Yes I'd say 5 amps)

Good.

Paladin06 said
* Measure Voltage at Battery Positive, (12.10 volts) Alternator Output (Bat), (11.12 volts) Red Battery at Starter Relay, (12.22 volts) and Bulkhead at Red Battery, (11.81 volts) Black Alt, (11.47 volts) Blue Run (10.47 volts).

* Recheck Voltage at Battery Positive.* Observe ammeter. Write down any change from first turning on ignition. (No noticeable change)
Additionally I checked voltage at the back of the amp gage and it was 11.47 at both post.

I've put this on the drawing...

Paladin06 said
These numbers seem all over the map to me but with 3 back surgeries they are the best I can do.

They're fine. Lets look at what they show.
12.1 Volts at the battery under a 5 amp load. OK. especially seeing the next reading down the line.
12.2 Volts at Starter Relay.
11.8 Volts at Bulkhead. 0.4 Volt drop in the wire is a lot. If real, could be a bad crimp connection at either end or the fusible link splice, (corroded or broken strands ).
11.5 Volts on both sides of the Ammeter and at the Alternator connection. No loss to speak of from the battery wire to the main splice. (Since there is no load and no current in the black wire to the alternator - it can not be assumed the alternator's bulkhead connection is good.)
10.5 Volts at Run. Must be resistance between the main splice and this connection.

Paladin06 said
After I completed all the test, I checked the voltage at the blue wire on the resistor. It was 10.47. It is now 9.58. WTF???

Also I noticed the red wire at the bulkhead under the dash gets noticeably warm while making these test.

Sounds like a loose connection or a wire with bad insulation? Is the red wire is the one from the main splice to the ignition switch?
If that's warm with just 5 amps, that's a major problem.