help with diagnosis

[v6tungsten]

My car stopped running today on the highway. felt like it was missing for a few seconds the check engine light, wrench lite up then car turned off.
Now car wont even turnover. acts like its dead battery but I know its good. tried jump starting but car but won turn over. Also connected my sct tuner and it cant read the stratigic code and errors out when trying to look at codes.

Car is a 2006 v8 manual with supercharger. I did pull the supercharger off and install a new bypass last week. also installed a new throttle position sensor off a v6 throttle body. Car ran for 30 mile and then just stopped.

Please help as now I have a dead mustang collecting dust in front of the house.

 

[TexasBlownV8]

Will the starter engage? What does the battery voltage look like? What happens i you turn on the lights or honk the horn? (If lights/horn works, you'd have a starting circuit issue).

What battery cables did you use for your swap?
What happens when you try to jump start it?

(will send you my phone number, leave a message if i dont answer and I'll call you back.)

 

[v6tungsten]

Will the starter engage? What does the battery voltage look like? What happens i you turn on the lights or honk the horn? (If lights/horn works, you'd have a starting circuit issue).

What battery cables did you use for your swap?
What happens when you try to jump start it?

(will send you my phone number, leave a message if i dont answer and I'll call you back.)

Nothing happens when trying to start it, jumper cables installed same thing. No sounds can be heard from the engine/starter. Sounds the same as when the old tuner sent a tune without the emobilizer set. starter wiring should be oem stuff. All electronics work horn, turn signals, ac, stereo. not sure on the voltage but i keep a trickle charger on the battery and it looked good yesterday. this started with engine turned off by itself on the highway. Also the fuel pump was working Thursday when installing the supercharger. I could hear the pump refilling the fuel rails after the install.

 

[v6tungsten]

found fuse 42 (engine #3) and 54 (pcm delay) blown. Lost Diode #53 so wont be able to test start the car until later. Now to figure out why both would blow at the same time and to double check other fuses. .50 fuse cost me $129 tow...guess it could of been worse.

 

[TexasBlownV8]

Ah, good you found it! I'll take a look at the wiring diagram and see if I can recommend something to check.

 

[TexasBlownV8]

Let's address each component:
diode "53" - how did you check it to determine it was "bad"? It would be either open or shorted. If open, there would be no key-on power to the PCM relay #1 nor to the fuel pump relay. A short would not likely matter. (You check the diode with a ohmeter in both directions, one will show high resistance/infinite, the other direction should show some value, unless the voltemeter does not feed enough current to make it forward-conducting). The diode is probably ok. It IS direction-specific. You can swap it with the a/c clutch diode to test it.

Fuse 42 - powers pcm and other things, including the noise suppression capacitors.
Fuse 54 - feeds the aux. relay box/delay for pcm-power off control. This should not normally be an issue, unless it keeps blowing fuses.

You mentioned that the noise capacitors were not connected, nor was the IMRC plug. Any of the exposed end of those connectors could touch metal and blow fuse 42. Or if some wire is not pinched somewhere.

Try replacing fuse 42 first, see what happens. But if it blows again, you have a short.
And tape up the imrc plug and noise cap plugs (or better yet, connect your 2 noise capacitors).

 

[v6tungsten]

I didn't do any testing on diode 53...I dropped it in the engine bay and it didnt make it out. I dont have the driver side noise suppression connected or motion plate. This is the first time any fuses have blown since i purchased the car in 2006. Once i find the diode and fuses i'll see if everything runs ok.

 

[TexasBlownV8]

OK As far as the unconnected plugs, tape them up good with good-quality electrical tape (not the cheap 79 cent plastic crap). Hide the ends in some loom, etc.; whatever it takes so the open connectors wont touch anything when bouncing around.

 

[v6tungsten]

Think i found the problem. The driver side front COP wire wore and grounded on the alternator. This is the second time ive had to replace that plug as the alt pushes on it. that woudl explain the miss i felt before the engine stopped running.

 

[TexasBlownV8]

Glad you found it. Can you reroute the wire so you dont have the issue?

 

[v6tungsten]

anyone have a link to the fuse listing for the 2006 mustang? AC wont run now and left my owner manual at work. Not sure what fuses or relay to check.

Car blows hot air now

 

[TexasBlownV8]

fuse 42, feeds the clutch circuit.

 

[v6tungsten]

anything else? 42 looked ok and i even installed a new 15 amp fuse and ac still blows hot

 

[TexasBlownV8]

how's the pressure charge? if its low it wont run.
Check the connection to the sensor on the a/c line, driver-side front by radiator.

 

[v6tungsten]

how's the pressure charge? if its low it wont run.
Check the connection to the sensor on the a/c line, driver-side front by radiator.

I'll check that to but ac ran fine before the fuses blew. I have a P0355 code and found one post that had the same issue and his AC wouldn't run with that code. I have a new cop and pigtale on order now.

 

[TexasBlownV8]

you could check the connector at the compressor (unplug it), see if you get voltage there when the a/c switch is on. You're probably not getting anything there. That's what I did on my v6 when fuse 42 blew, and traced it back to the blown fuse. (pick wire to the a/c compressor runs from the BEC back connector, from a/c relay)

 

[v6tungsten]

AC started working after new COP install and P0355 code cleared.

 

[petersonb]

Think i found the problem. The driver side front COP wire wore and grounded on the alternator. This is the second time ive had to replace that plug as the alt pushes on it. that woudl explain the miss i felt before the engine stopped running.

Reviving this thread to add another data point, and the keywords Department of Boost DoB GT450

Mine did the same thing. Minor design flaw. Too bad cant just turn that coil pack around 180deg.

Cut, solder, shrink tube, elec tape, conduit. Hopefully it's got sufficient protection now.

I have been blowing #42 "Engine #3" and the PCM 10A fuse a couple times a day for the last week. Super annoying.

#42 also powers the coils, as I understand it. Didn't know about the A/c clutch, but that's convenient to know, too. Winter in Utah.... Haven't been running A/c much lately...