also, code reader cant establish connection to read codes, I have checke the fuse. wiring doesnt appear faulty, any ideas on where to go from here? 2004 f150 supercrew lariat fx4 5.4 3v

 

how old is your code reader?

the 2004+ F-150, and 2005+ for all the other Fords operatate on a OBD-II Can Bus Network

so if your scanner is slightly older, it won't be able to talk to the OBD-II scanner. If that is the case, I recommend you pick up a new scanner that can communicate with all 5 of the current OBD-II protocols.

as far as i can tell, there are the 5 total protocols:
2 american
1 german
2 japanese

 

thanks
its not the reader, I also had it a ford mechanic with a snap on who checked it also, he said check the fuse and wiring. all seems well, so I am a little lost on where to go from here thanks again

 

Your options are to either take in to the shop or find a Powertrain and Emmissions Control shop manual for 04 Ford and follow the diagnostic routine for the symptom, which in your case cannot retrieve codes. Most of the shop manuals I've seen with this symptom usually point to a problem with wiring or PCM. Sometimes you can find the shop manual at your local library.

 

See if you can pull the DLC (or leave it if its comfortable) and probe the pin on the connector for voltage with a meter. It should be a Lt. blu/white wire.

If you have voltage, check your right front footwell for a landed ground point and trace the harness back. Its looking to be a solid blk wire in the DLC harness. Make sure all the wires don't seem to be nicked or "disconnected". You are looking anywhere prior to the grnd point. Only because it seems that particular point has the mainhdlight switch and a few other important components attached.
Obviously if the point was bad you wouldn't have any of these functions.

...I'm checking and following the PCM harness now, if I see anything I'll update this response.

Update: The PCM seems to have 3-wires going to the DLC. Should be... 13-Violet 10-Pink/Lt Blu 2-Tan/Orange (numbers represent the position in the DLC connector). Maybe try to find a way to ohm out these connections?

Also, There is another grounding point landed "At right rear of engine compartment".
(Ground location G101) The wire should be Blk/Wht

 

wow!
thanks for that. I will check these points today and let you know. that the info Im talkin about thanks again!!

 

ford dealer read the codes, didnt say they had a problem. must have been the scanners. thanks again