Re-wiring an '80 fleetwood brougham engine compartment

[80Caddy]

Im down to the final stages of my resto of the caddy. At one point or another this Cadillac was re-wired to handle newer batteries.

I can do any mechanical repair needed, but when it comes to electrical, im totally clueless.

Ive got a phantom drain somewhere, and the fuse panel is a mess of broken wires and jumpers.

I dont know if this thing was re-wired to the same diagram, or what was involved in the re-wiring process (ie: what was done).

Im basically looking at re-wiring the engine myself, cause i have no idea where to even start checking for where the drain is.

Has anyone partaken in a job such as this before?

Is there a specific method to testing for drains?

Im looking to do this myself, as ive never done it before, and would like to learn.

Any ideas greatly welcome

[KHE]

Disconnect the negative battery cable from the battery and connect a multimeter set to the amps scale in serieries with the opened connection. In other words, connect the negative nead of the multimeter to the battery negative terminal and the positive lead of the ammeter to the negative battery cable that you disconnected. Note the reading on the meter and then pull fuses one by one until you see the current reading drop substantially - that will be the circuit where the parasitic drain is located.

[80Caddy]

Disconnect the negative battery cable from the battery and connect a multimeter set to the amps scale in serieries with the opened connection. In other words, connect the negative nead of the multimeter to the battery negative terminal and the positive lead of the ammeter to the negative battery cable that you disconnected. Note the reading on the meter and then pull fuses one by one until you see the current reading drop substantially - that will be the circuit where the parasitic drain is located.

Awesome, Will try, thanks!