at the cost of a few cents . would you not change the diode anyway?
i usually run three 3A as a gang ( yes i know they dont shed evenly as they warm ) so i have a proxy 9A
only time ive seen it go bad, and they tested ok to me on DMM
but still one must have leaked was the relay would buzz when the light was activated until the alternator kicked in
Yeah running 2 axial 6amp diodes in parallel, very strange never seen a diode reverse bias and read correct on my DMM in the 20 odd years of doing electronic (switchmode PSU's repairs)...Learn something new everyday
Ok will buy a few more and see if that fixes the issue.
Appreciate your help mate!
Ok today I replaced the diodes and still wouldn't switch off with key
Thought to test back feed on the ignition wire I soldered in a diode as in pic below, and it functioned as normal and turned off with key.
That would suggest the internal regulator does indeed have a inbuilt diode to prevent back feed to ign wire. So time to have the alt rebuilt