04' (40th Anniversary V6) New Battery, Tune-Up, Ran Great... Now No Power Or Communication With Comp.

MotorCityMostang

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Sep 28, 2019
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Purchased this vehicle from my neighbor,, the car sat in his yard for over a year and told me he could never get spark or fuel pressure.. so i bought it as is with some body damage on the passenger side from an accident.. I inspected the engine compartment, all fuses/relays, and installed a new battery.. I got spark right away then squirt a little fuel into the intake and it fired right up.. I then made the choice to start the bodywork and diagnose the fuel issue... SOMEWHERE along the way in this process the car lost spark then the computer quit communicating by just showing dashes across the odometer and now there is nothing registering on the dash and nothing will come on.. Where could I locate some information or possibly factory procedures to troubleshoot the Ford/Pats systems?
 
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wmburns

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Aug 14, 2009
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I then made the choice to start the bodywork and diagnose the fuel issue... SOMEWHERE along the way in this process the car lost spark then the computer quit communicating by just showing dashes across the odometer and now there is nothing registering on the dash and nothing will come on.. Where could I locate some information or possibly factory procedures to troubleshoot the Ford/Pats systems?
IMO the clue to your problem lies in the description. IMO this is NOT a PATS issue. Likely this is a PCM power problem.

Review the link below.

1996+ Crank with no start check list

Pay attention to the part about testing and confirming the state of real key on power in and out of fuse F2.34, F2,2, and F2.8.

Have you checked all of the fuses in the battery junction box (BJB=F1)?

Also pay attention to the part about:
  • what the check engine light is supposed to do during cranking. This can also offer clues about the state of the PCM (alive or not).
  • The part about what it means when the cluster displays all dashes.
If you are looking for an educated guess. You stated that there's some body damage on the passenger's side. Guess what is located inside the front right passenger's wheel well?............

The CCRM power relay. Which if the wiring were damaged would be expected to CAUSE your symptoms.
 
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MotorCityMostang

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Upon further testing i found the starter and wiper relays did make the 'clicking' sound but they did not allow current between 30 and 87 when 12V was applied. There is NO amp rating anywhere in the BJB schematic. The part #'s are also gone. I cant seem to find any info on OEM spec;s for these relays! The parts houses seem also to be clueless as to finding any reliable info. Is there a source for FORD relays they are keeping from us? PLEASE HELP
 

wmburns

SN Certified Technician
Aug 14, 2009
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Houston Texas
Upon further testing i found the starter and wiper relays did make the 'clicking' sound but they did not allow current between 30 and 87 when 12V was applied. There is NO amp rating anywhere in the BJB schematic. The part #'s are also gone. I cant seem to find any info on OEM spec;s for these relays! The parts houses seem also to be clueless as to finding any reliable info. Is there a source for FORD relays they are keeping from us? PLEASE HELP
Just wondering. Did you follow all of the information given in the "crank with no start" thread? Including the attached diagrams? Especially the fuse panel diagrams.

Regarding the question about 30 and 87. Did you confirm there is power to being with in terminal 30 to begin with? Is there key on power in and out of fuse F2.26?

There was some real good trouble shooting information already giving. With a few simple tests it's possible to learn a TON about your problem.
 

MotorCityMostang

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The trouble shooting guide was invaluable,
The only part I didn't see in that thread was the real power key on at F2..also sorry what does the .26 mean after F2? I see there are lots of F2's I'm a little confused as to what it signifies.

Maybe it's in another thread, I printed the thread 1997 won't ignite.

Also the check engine light will b helpful once I can fine the correct amp designation for the 3.8L

All the schematics I have been able to track down all show dashes in the amp column for all 5 relays in the BJB.

I'm looking also for a complete colour wiring diagram like every other new mustang owner so I'm still searching for that.

I'm sure that power was crossing the circuit in the BJB but I was unable to verify the real power key on.
 

wmburns

SN Certified Technician
Aug 14, 2009
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Houston Texas
OK. Here goes.

F1=BJB=Battery Junction box=the fuse box in the engine bay.
F2=CJB=Central Junction Box=the fuse box in the driver's kick panel.

Sooooooooo Fuse F2.26 is fuse #26 in the Central Junction box. Make sense?

Fuses F2.34, F2.2 and F2.8 are also in the Central Junction Box. #34, #2, #8.

Also note that most of the fuses in the BJB=F1 are "always on" circuits. So if there's no power into a fuse of an "always on" circuit then your problem is more basic. IE right inside (or power to) the BJB itself.


1999-2004 BJB CJB fuse panel layout:
 
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