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Datsun 510 - KA24E - No spark when cranking


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Been working on a KA24E in a 71 510 with a CAN/AM box.


Having a weird issue where the run relay loses power and shuts off while cranking and as a result, the coil loses power. Is that normal?


When the ignition switch is in the 'ON' position, the run relay has power and I get spark by manually turning the dizzy.

When the ignition switch is in the 'Start' position, starter spins the engine, the run relay loses power and then there is no spark.


According to the ignition switch pin-outs I've seen, the run relay should have power via the Black/White wire while in the start position. See two diagrams below.


I've tested two ignition switches, both of them do not have continuity though pin 1 and 2 while in the start position. It's possible they are both bad. I've never used them before and just dug them out of a spare parts box.


Can anyone confirm pin 1 (White/Red) and pin 2 (Black/White) should have continuity while in the start position? Do I have two bad switches?









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When I did the ka swap on my 720 I had an orange wire that ran from the harness to the starter solenoid. It has to be hooked up or no spark. My memory is shit but I definitely remember the orange wire.


I've got the orange wire hooked up. What does the ECU use the start signal for?

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Shoot Jeff a message, might be your best bet!


Could also be something you missed, step away for a while then get back on it and go through all the hook ups.



If you look a the Run relay, it's pretty much the simplest circuit. Power comes directly from the fuse box/ignition switch. The ground, is simply ground.  I'm going to run through it again, but it appears to be a bad switch.. or two. That seems really unlikely... I wonder if Al has a few spares.

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You are probably on the right track with the switches. I actually had my ka on a run stand and wired in a simple ignition switch from a boat diesel that combined acc, and run and worked fine. Long ago I made a wire octopus of 4 wires with spade conecters on three combining source hot, acc,and run. The 4th was bare just to poke the start circuit. Worked fine and yes I am a redneck!

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Was able to find a D21 ignition switch that is the same pin-out. Popped that in and got spark when cranking! 


Didn't think I'd have two bad switches... but I did. I'll pickup a stock replacement switch for the dime.



Thanks for the input!

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Had to be something simple, I sent a message to Jeff yesterday regarding a question I had and he told me all I need to hook up from my chassis are 3 wires.... ignition, power from battery and a ground, the rest are from the S13 harness/ECU.


I'm glad you found your gremlin!, I'm wiring up mine this weekend ;)

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Timing chain rattle?


Naw.. more like valve train noise. Something in the head.. I don't know much about this motor. Leak down was okay, but could have been better. I have a spare head if things go south.. but that's why this is not being installed in my 4 door. Working all the bugs out in the mule chassis first.

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