The Mitsubishi 115 amp alternator which you have is normally set up with four wires on the D2-40 engine. They are:
Red wire- Connected to the B+ terminal on the alternator and connected to the #30 terminal on the starter motor
. This is your main charging wire and is connected to the start battery via the starter motor
Black wire- Connected to the B- terminal on the alternator and also to the block ground lug. There may also be a smaller black ground wire connected to the B- terminal which is the ground lead for the engine wiring
harness. Its possible that this smaller black ground wire is connected directly to the block ground lug.
Yellow wire- Connected to the "S " (sense) terminal on the alternator and also connected to the #30 terminal on the starter motor. This wire allows the voltage regulator
to feel the voltage level of the battery more directly and maintain closer control of the alternator output level. If the alternator output is hooked up thru a diode isolator the yellow wire should be hooked to the house battery terminal on the output side of the isolator to allow the regulator
to feel the voltage level of the house bank.
Brown wire- Connected to the 61 terminal of the alternator. This is the energizer wire coming from the MDI box to allow the alternator to energize and begin charging.
You can connect the alternator directly to the house bank by removing the red B+ wire from the alternator/ starter motor and running from the B+ terminal of the alternator to the house bank. You need to be aware that the wire gauge will have to be increased to accommodate the additional distance which this will most likely entail. You should also move the yellow sense lead from the starter and lengthen it so that it connects to the house bank, thus allowing the regulator to sense the voltage level at the house bank.
It goes without saying that both battery banks need a common ground to each other and the engine block.
If you run the B+ charging lead directly to the battery instead of thru a switch, ( or even if you run it thru a switch) you need to be aware that the B+ and the yellow lead need to be fused at the battery end for safety
A comment regarding the "Echo Charger"........I have no experience with this unit, but from a quick look at the installation
instructions it seems that the charger
will cut on and off as the voltage at the start battery fluctuates. This is almost guaranteed to cause the charge alarm
in the VP alarm
system to activate, and this can be a nuisance.
Hope this makes some sense.