12V relay + diode question
i'm running a relay, triggered by 2 input voltages. for one input i'm using the 12v ACC line, the alternate input is 12v from the PSU.
obviously, the std relay i'm using only has one trigger, so i'm using 2 3A/20V diodes to isolate the 2 lines. this setup was working until 2 things happened. 1) i permanently soldered the diodes on, and heated them up too long and burned them up (voltage passed both ways). 2) i wiggled the relay too much and broke it.
so i've replaced the relay and diodes. the ACC line is hot and hooked up properly. the PSU 12v is hooked up properly and is hot. the diodes are preventing feedback correctly.
the problem is, if i turn on the ACC, then the PSU, then the ACC off, the relay clicks off. it should stay on cause the PSU is on. basically (tested) the PSU is not switching the relay.
so... not enough power? its hot at exactly 12v, i'm not sure what else would be the problem. help?!?