Just finished engine swap. Crank no start.

[BlakePorterMcLain]

 

[BlakePorterMcLain]

I’m suspecting no spark, or bad gas but was wondering if anyone knows what this plug goes to, there’s 2 on each side, both at the end of the wiring harness. Was thinking it might be lights but nothing lighting wise plugs into these. Any ideas?

 

[whtbronco]

I have mine taken apart right now and can't find a connector that matches in that area. Where does that trace back to? Also what model year and engine?

Anyway, my original thought was mass air flow sensor, which would prevent starting. It is a 4 pin connector and in that area, but mine is round. I have a 2004 with 5.4L 2V.

 

[BlakePorterMcLain]

Post a picture of the connector. This is not mass airflow, it comes off of the harness that the lights are tied into but it doesn’t match up with anything for lights. Theres one on the other side as well and it comes off of the engine harness wires at the very end towards the radiator. Mine is a 2004 4.6 2v

 

[whtbronco]

Ahh then I wonder if it's for fog lights. If so it would require an extension wire that changes the connector style. I can't think of anything else that would be on both sides and that is so dirty it's not likely that it has been connected recently.

 

[BlakePorterMcLain]

Ahh then I wonder if it's for fog lights. If so it would require an extension wire that changes the connector style. I can't think of anything else that would be on both sides and that is so dirty it's not likely that it has been connected recently.

So I figured out that it’s only for the driver side. The plug on the passenger side was crank position sensor. It can’t be for fog lights though, those plugs are hooked up properly.

 

[whtbronco]

Oh and now I see your truck in your avatar and it has fog lights, sometimes I'm just not that smart . I was kinda thinking you didn't have fog lights. The only thing on the driver side engine bank harness on my truck like that is the cam position sensor.

 

[BlakePorterMcLain]

Oh and now I see your truck in your avatar and it has fog lights, sometimes I'm just not that smart . I was kinda thinking you didn't have fog lights. The only thing on the driver side engine bank harness on my truck like that is the cam position sensor.

Passenger side was for crank position sensor, driver side is for crash sensor

 

[whtbronco]

Hmm, I would never have thought it was for an in impact sensor. I'm not sure I have even seen one on the Expedition yet. Glad to hear you figured it out.

I've dealt with impact sensors quite a bit on my daughters Monte Carlo. All of those have yellow connectors or a yellow portion of the connector. I assumed since they are part of the air bag restraint system. Sometimes I unfortunately make improper assumptions.