In the process of trouble-shooting my electrical system (another story), I came across this power diode in the engine compartment fuse box. It appears to be in the circuit that activates the PCM power relay (in the same fuse box). I've always tested diodes by checking the continuity twice, reversing the leads each time. If it works one way but not the other, diode's good. My diode, however, shows overload both ways (that would be infinity on an analog meter).

But, my meter only measures up to a thousand ohms, so anything over that would probably also show up as "OL". How can I tell if this diode is any good?