Hei /6 won't shut off?

Just saw you post about still wants to run-on. It most likely has to do with undesired relay coil activation by a leakage current. The first thing to do would be to use a meter to view relay coil voltage. Then see what happens when the key is turned off.

12V relays typically need about 100mA (0.1A) on coil to pull-in, but holding current may be about 1/4 of that. The added diode should have blocked the charge indicator lamp from sourcing from the alternator on shut down. Does the indicator lamp light with ignition on before starting? It should if wired in correctly. It should also block voltage that the alternators sources at that point on shutdown. The indicator is illuminated when the indicator circuit is low (alternator not putting out), the diode offsets that off by about 0.7V but the indicator will still light.

If the indicator is working, then there might be another leakage path on the switched ignition source.