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ka24de swap 720 wiring issue


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I have currently swarped a ka24de into my 1986 720. The lower wiring is perfectly fine it cranks and everything.I followed the upper ka24de wiring harness diagram from a forum using 3 relays but my relays aren't closing. Could this be a bad ecu but I haven't tried using direct power to all my wires. Has anyone experienced this issue cause isn't the ecu suppose to ground the relays to create contact?

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My first question - Is your ECU turning on? There should be a red, or a red and green LED bulbs in a small window on back of ECU. Are this illuminated when key is turned on? 



Icehouse has put a HUGE amount of work on creating these very helpful diagrams, however they can be a little confusing to understand.


I've taken the time to "redux" his diagram to help others who choose not to use his Can/Am Box. While it's a great invention, not all of use can afford to buy it.


This is a very, very simple wiring job. I drew this diagram and then used it when I wired my KA24DE into my '79 510. This is 'literally' all the instruction you need to wire up a dohc KA.


NOTE:  For whatever reason, maybe my own fault or possibly my ECU (i dropped it - doh!), my fuel pump would not prime, nor would it pump while cranking or running. Therefore, I decided to just put it on it's own switch. This also served as a kill switch so it can't get stolen. 


If you follow this diagram and your fuel pump doesnt work, just put it on it's own circuit with a switch.



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Standard bosch relays fork fine, thats what I used.


If those lights are not turning on, you are not getting power, or you have a bad ground. 


Ecu's dont "just go bad". It's highly unlikely the ecu is bad. 


Check my diagram with you're wiring. 


Let me know.

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