2012 apex cranks and fuel pump kicks on only when cranking

[tangerine427]

I have a 2012 Nytro that has a 2012 Apex swap done. Complete new yamaha apex harness ecm and all sensors. I turn the key and get no typical fuel pump with key on. I can hear relay and watch the ground from ecm switch it off. I have replaced the fuel pump relay with 3 known good relays. I have no corrosion on my starter relay. I have swapped it with another apex starter relay that is good. When I crank it over I get power to the fuel pump. Sled pops and wont start. I have checked all ground locations and everything is clean. Any ideas? TY

 

[Stubbs]

Sounds like something is not pinned properly in the harness. The fuel pump needs 12v with the ignition on, and in the crank position. Sounds like it’s only got 12v in the latter. Have you tried feeding the pump 12v from an auxiliary source to see if the sled will run?

 

[tangerine427]

I jumped power from the keyed on power red/wh to the red/blue to pump and it will stay running. But with code 43 flashing because of an open circuit.

 

[Stubbs]

Sounds like it’s either not pinned properly/the same. Have you checked to see if the ignition switch pin placements are the same for a Nytro vs an Apex?

 

[tangerine427]

I’ll double check. The ignition switch is from the apex. All wiring is apex except headlight harness is modified.

 

[tangerine427]

Found the problem. My starter relay was installed with power in the wrong side and wasn't getting 12v with the pin under the 8mm bolt to the fuse. Dealer reinstalled that backwards. Ugh. but it is found now.

 

[Stubbs]

That’s fantastic!!! Although the relay’s look identical, the part # for the 3 cyl and 4 cyl are different, and that’s why.
I’ve often contemplated buying a nytro tunnel, bulkhead, and transplanting my Apex 4 cyl and electronics into it.