Datsun Roadster Forum-311s.org

Ignition switch and/or solenoid as mentioned before is likely. When you turn the key it surges a bunch of amps through the switch to kick the solenoid. A relay will get the amps out of the switch and help save your switch. And if you have the 3 pin 67.5 switch good luck getting a replacement. I know some have swapped in the 5 pin switch.

Heat can make the solenoid finicky. While I haven't put in a relay I do have the gear reduction starter and what a difference it makes. Since I have a 66 and 67 I put in a Ron Francis switch and don't have to care if it goes bad.

This is interesting. As the original starter of this thread, my starter basically froze up a few weeks ago. I had a couple of spares, so I just threw another one in. It isn't the nice compact gear reduction starter that I had installed, but it works just fine. I'm now thinking the starter itself has been having issues for a long time and finally failed. I had also been blowing an inline fuse that I had installed between the battery and amp gauge regularly, usually while starting. I haven't blown one since I changed out the starter.