New engine won’t start

Hey new to the forum me and my buddy just put in a used jdm 3rz into his 1996 taco and we got it all installed and hooked up and when he got the motor from the import place they said use all the original sensor and parts from his truck and just use the jdm block and head so that’s what we did we hooked everything up and went to start it and nothing it just has the battery light, oil light and check engine light on the dash but the key dose nothing and that’s the only power the truck has nothing else’s works in the truck just those 3 lights and the door chime also when we try turn the lights on the same three light on the dash light up and it clicks but lights are still off any ideas?

 

Could be a loose ground or connection, battery could be weak, have you tried boosting it?

Is it auto or manual? If its auto we know the engine isnt seized but if its manual did you turn the engine at all?

Lastly, I've had bad luck using engine harnesses supplied with used engines. They can be pinched or damaged and really hard to find. Especially with a JDM engine you're better off re-using the existing engine harness.

 

We used the original harness there wasn’t much left of the jdm one just just cut all the wires and hoses and yeah the battery was our first thought so we boosted it and still nothing and as for grounds the ones thing we had a slight issue with was the main ground for the battery we could not remember which one of use unbolted it and from where so I looked and found a threaded hole on the block and put it there is there an exact spot it’s supposed to go also I have a video of trying to crank it if that would help

 

Did you use the old starter from the original engine?

They are known for contacts and could be part of the issue. But I usually suspect connections first with an engine swap.

Also you can use booster cables to help the ground from the battery to the engine block to see if it helps.

 

Yeah we used the original one but it was working fine before the swap only reason we had to do the swap is because he somehow put at rod through the block and yeah I will try that tomorrow with the cables is there anything else that we should try? I’m trying to gather as much info as possible and get some things to test before going back to work on it

 

If all else fails I bench test the starter, I'll remove it and shoot power straight at it and see how it works outside the truck.

It's clearly getting power, but is it getting enough. A voltage drop test is the right way to do it, but harder to explain.

 

I think I know what to do for that isn’t that were you test to see if the the truck is pulling power when trying to crank by holding a multi meter on the battery I’m probably wrong about that also another thing is the old motor leaked oil like no other she he pressure washed the engine bay out before dropping the new motor in but he put the harness up on the windshield so he’d have less chance of getting water in it

 

Check 4 pin connecter under fuse box, three go to alternator one (black) is start trigger check for 12v when key is rotated to start, then check continuity to starter, good luck.