Swapping Front Electronics Module, (03 V8)

[Torx]

Ordered an fem off ebay, should be here tomm.
Still on the quest to figure out my electrical problem.
alternator and battery is fine..

dash cluster still goes out off and on, when it goes out i have no power steering nor can i crank the car.
I have to put the key in, turn it to run but not crank it. I have to wait sometime between 20min-50min before the dash cluster flickers on to where i can crank it. Its so stupid. Then when i get running it'll go back out off and on. Very frustrating.

At this point i dont know if its the FEM, REM, Key tumbler, PATS, or Door module.
I spent a few bucks on a used FEM so i wanna swap that tommorrow, but need to know the risks if there are any.

If i disconnect the fem from the wiring harness will i completely ruin or disable the car from here on out?
Would it need reprogramming, or could it be a gamble to work or not?

 

[joegr]

Unlikely to solve your problems, but should be low or no risk to try.

 

[Torx]

ok. joe, are you still confident its my alternator? you mentioned it before, but dont understand what about the alt that could cause this if the car isnt even running.

 

[LS4me]

ok. joe, are you still confident its my alternator? you mentioned it before, but dont understand what about the alt that could cause this if the car isnt even running.

The LS is EXTREMELY electrical sensitive. Did you test the alternator? What voltage was it putting out with the car running? ANYTHING less than 14.4V means the alternator is on it's way out. When my alternator died (taking the battery with it) my speedo said I was doing about 125, the tach was around 6K yet I was barely doing 25!! The LS does many, many oddball things with a dodgy electrical system.

 

[1LoudLS]

ANYTHING less than 14.4V means the alternator is on it's way out.

I wouldn't say that "ANYTHING" under 14.4 means the alt is dying... under heavy load, 14.2 or 14.3 would be acceptable.

 

[Torx]

havent been able to crank the car since friday to test the alt voltage again.
popped in the FEM, still same problem.
might spend on a cheap REM next.

what are the chances its my keys or tumbler?
because either key when put into the door lock doesnt want to turn left or right, i have to sit there for a bit and jiggle wiggle before i can unlock.
is there something going on with my keys chips, and the PATS? Weird, as i should be able to put the key in anytime and turn left or right as i feel, but its locked up in there and randomly lets me unlock/lock. wtf bros.

and when i do lock my car, my alarm led doesnt flash at all.

back on the alternator, how can all these electrical issues be happening when the car isnt even on, unless theres voltage going through the alt at the time of key insertion and creating erratic voltage gremlins?
also, if i can crank the car and drive a distance and the dash cluster is still on and i turn the car off.. lock doors, unhook batt. Then come back later the dash will come right on and i can crank up.
but if i turn the car off with the cluster out, i cant crank it up later.. weird as heck

also, the cluster seems to come on better when its cold outside.
but when its hot hot, i have to sit and wait forever for the cluster to wake up just so i can crank the car up. wtf

EDIT: battery disconnected 12.60. Batt connected 12.55 and drops slowly. Cant crank car up to test alt voltage. Have already jumped off, and still no cluster on and thus cant crank. Same issue even when jumping from another car.

 

[Torx]

update:

so after the car sitting up for a week not being able to crank up, i go out and wow dash comes on just long enough for me to crank it up.
so i run it around the neighborhood for a while, come back home check voltage. 13.7v idle, 14.0 on a high rpm (dont know what rpm because dash out)
I dont know if those voltages are low because the battery has been sitting half dead, or if thats the alternator for sure.
I've got money saved up for whatever high expense now, so i can either wait for it to crank up again some time this week and take it to a shop, or replace the alternator myself and take a gamble that that is the problem for sure.

 

[LS4me]

update:

so after the car sitting up for a week not being able to crank up, i go out and wow dash comes on just long enough for me to crank it up.
so i run it around the neighborhood for a while, come back home check voltage. 13.7v idle, 14.0 on a high rpm (dont know what rpm because dash out)
I dont know if those voltages are low because the battery has been sitting half dead, or if thats the alternator for sure.
I've got money saved up for whatever high expense now, so i can either wait for it to crank up again some time this week and take it to a shop, or replace the alternator myself and take a gamble that that is the problem for sure.

That idle voltage is too low, IMHO... Especially without a load. I believe you need a new alternator AND battery.

 

[Torx]

Ford Dealership wants 1700 to replace the guage cluster because of a "short". Honestly this sounds like a copout. I asked the guy if the tech tested the alt, batt, pcm and modules. Tech didnt. He literally spent less than an hour. Just looked at dash and said its a short. Wtf kind of nonsense is that. Im out 130 for diag, and car is stuck there. Those jokers are trying to set me up to trade it in because i sure as heck aint paying that, nor do i want a car note. This will be the last time i do business with that dealership. Im undeniably frustrated now.

 

[oddball]

They should have been able to connect their current tool to the diag port. If it can't talk to the gauge cluster, then the only response is to replace the gauge cluster. You can run through the diag tree in the online '06 manual also. The other main option would be a partial wiring fault, which are tons of fun to find.
Replacing the gauge cluster requires the dealer to re-authenticate the module to the other modules. The car is inop until that is done, and can only be done with their tools. I can't remember if the gauge cluster also does the key authentication - they may need to re-auth all your keys too.


13.7V idle is low. I normally see 14.0-14.1 *after* running for half a minute or so.

 

[joegr]

... The car is inop until that is done, and can only be done with their tools. I can't remember if the gauge cluster also does the key authentication - they may need to re-auth all your keys too.


13.7V idle is low. I normally see 14.0-14.1 *after* running for half a minute or so.

Actually, there are some consumer scan tools that can do this as well. I have one, but it was pricey. (I wonder if Forscan can enter secure mode and do this too? It would be a cheap way, if so.)
Yes, all the keys have to be re-added. You must have at least two unique keys for it to work at all.

While it could be the cluster, it could also be that the cluster isn't getting good power. This could be wiring, a ground, or a relay in the trunk. 13.7, even at idle, is untypically low for an LS, AFAIK.
It is easy enough to measure the power supply voltages at the cluster when it is not working. That should quickly solve if it is the cluster, or if it is something else.

 

[Torx]

ok, good advice, thx guys. if i can get it back home, imma take the dash apart and take a look myself and take another look at alternator.
is there any pinout schematics for the wiring harness plugs that go into the back of the cluster? I can get a 50-100 cluster off ebay but they want 560 to reprogram it.

 

[joegr]

Yes, I have that. Give me a little while to scan it.

 

[Torx]

ok thx joe. another side note, around the time this started happening is when my left turn signal cluster bulb went out. Dunno if thats coincidence but i might look into that too.

 

[joegr]

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