Won't start one day and fires up first crank next day
The 5th wire on original factory ECUs was a part of the internal power control. Later the factory and aftermarket was able to incorporate solid state control into the units.
The ECU draws only a little power as all it does is amplify the magnetic pulse (wires to the distributor). Then use that to make and break the primary coil circuit, same as points. The transistor on the top does get hot but we're not talking about more than an amp or so as far as draw.
I suggest not using a relay unless you get in a bind, especially if the resistance in the R6(alterntor out) or J1 (switch feed) connections.
If you want to make nice factory like connections, get some open barrel crimpers and selection of Packard type 56 and 58 type terminals.
The 5th wire on original factory ECUs was a part of the internal power control. Later the factory and aftermarket was able to incorporate solid state control into the units.
The ECU draws only a little power as all it does is amplify the magnetic pulse (wires to the distributor). Then use that to make and break the primary coil circuit, same as points. The transistor on the top does get hot but we're not talking about more than an amp or so as far as draw.
I suggest not using a relay unless you get in a bind, especially if the resistance in the R6(alterntor out) or J1 (switch feed) connections.
If you want to make nice factory like connections, get some open barrel crimpers and selection of Packard type 56 and 58 type terminals.