An example;
From stereo experience, You can kill a amp with too little power (overheating). You can also kill subs with too little power (overheating). Of course you can kill subs (injectors) overpowering too. I would think that some ficm problems come from injectors trying to take more power than the ficm is actually producing thus burning (evidence of failed solder connections) the ficm up, overheating due too not enough power. Now this may not make sense as I am not good at expressing what I think, but I am trying to get better! lol

 

You are on the right track.

Without getting into details, I spent a fair amount of time doing FMEA on that part and have theories.

A few tips: on the E van, it is mounted on the body and not on the engine --- and it has far fewer failures.

Beyond that --- I am afraid I just NDAed myself from talking further on the FICM failure issue.

You can read my posts on that right up to a few days ago.

Car stereos have quite a different profile --- of energy demands --- and it is much less stringent to meet specs for a high output alternator for car stereo use than it is for a continuous load.

 

Just remember that power is defined in watts and if the voltage decreases the current must increase to maintain the desired power( watts).
Increased current results in increased heat in circuits not designed for the increase in current. Insulation is rated for voltage. If you increase the voltage to far to decrease the current then your insulation breaks down. Everything is a trade off in anything designed right down to the minimum allowable standard.

 

One of the weakest links in the system may be the dielectric coating on the coil wire.

 

OK. This is going in the wrong direction. Even though I find it interesting about the whole 48 volts vs the 58 volts and I could see when 58 volt setup might help you maint 48 volts if your battey voltage was to drop to low in cold weather. This does not help my last question.....

I did the whole re-solder thing but I still can't get my voltage up to 48 volts however if I take a wire and clip it to one of the cooling fins then clip the other end to ground. I have 48 volts all day. Both KOEO and KOER. I do see a spot on the back mounting bracket down towards the bottom mount there is a stud. Mine is rusted over so nothing has been attached there for a while. Should there be a ground wire going to one of the mounts?

 

I havent done mine yet, with that said look for evidence of a ground strap (rusted off) somewhere. You did say you tested with koer and koeo? I would say that the ficm is looking for some sort of ground?. Maybe you have a grounding strap off the engine somewhere? Sorry as I am learning this too.
When you had it runnin, did all seem well?

 

I don't see anything in any of the diagrams or procedures in the service manual that indicate there should be any grounds other than the ones through the connectors. However the wires coming out of those connectors have to go somewhere, and at the other end should be a grounding terminal, probably on the engine.

Below is a picture of the FICM, with the connector for power and ground indicated. You can try following the wiring loom back and look for where it grounds. Any grounds you can find on the engine should be cleaned up anyway. If you have one bad one, you may very well have other bad ones.

It's interesting to note that a bad ground can apparently cause low voltage in the FICM. That would make sense, but so far as I know it's never been mentioned as one of the things that should be looked for when diagnosing FICM voltage issues.

 

I should have stated that also. I did check the gounds on the pins and all is good. It also checks out with pin 2 on the test pins. 1 being closest to the intake. Pin 4 being to one to check for the 48 volts.

 

c1388c grounds the unit thru pin 1, 2 , 3 , 22, 26. If u unplug the connector, and put the side with the line 1/2 moon shape pointing to the right, the top rt is #1, Middle rt is 12, bottom right is 22. All 4 of those wires splice into one ground black and pink wire... follow c1388c back a little toward master cylinder and u will find a 8 pin rectangualr connector that runs the ground through it on pin 1. It retains the bk/pk color and goes over to the inside of the drivers fender about where the hood shock is to ground it to the body. Looking at the picture it should be mounted to the inside of the drivers fender about even with the end of master cylinder.

 

I can't remember his user name exactly (bvanbeck???), but he found that he was getting several injector circuit low codes and his issue was that the harness ground was faulty. My FICM harness is grounded to a stud on the intake manifold. Probably convenient for the engineers but maybe not necessarily the best for the connection over time.

 

Thats the thing that is puzzling me. I have checked all that. It grounds right above the power steering resavor. All of that checks out. So the unit has grounds going to it. The only thing I can think of is something came loose inside the FICM. Oh and I am not getting any codes. It just will not start in cold weather. Now before we go into everything else to check. The glow plug system checks out. Run time is about 1.5 mins. Pulling 45 amps per side it settles down after the key is turned on. Thought maybe it was a oil issue. Changed to 5w-40. Changed the batties out. I have power service in the tank. Don't really think it is a fuel issue. If I plug it in it will start hard but will start. After about 3-5 mins it smothes out. That brought me to the FICM. Tested the 4th pin and got 48 volts KOEO but it dropped to 25 volts KOER. Pulled the unit. Followed the re-solder process. Put it all back in. Still not any better. Hook a wire to one of the fins the other side to ground and the injectors took off buzzing. Checked the voltage and I have 48. Started it up and I have 48. All is good. Now I did but this used back in March so I have no idea what anyone else might have done with it.

 

Faulty ground sounds like a good hypothesis.

Follow it.

 

Does your FICM mount like the one in this picture: Page 10: Component Locations ?

i.e. is it an 03 motor in an 04 truck?

Have you checked the ICP/IPR?

 

I did check the ICP. That checks out also. Everything is pointing to the FICM. I ground the case last night and parked it out side. Right now it is +14 out. I will see if it starts and re post. My feeling is that now I have 48 volts at the FICM and the injectors are buzzing it will start right up. By the way it is a 04. The mounting bracket is not the same as the one in the picture. But it is in the same place. According to the manual it is a late model motor. I know Ford had a early and late model motor in 04.

 

If you got it to work grounding the case, you cannot rule out bad connector / bad contacts / bad harness.

Since the way to "fix" that is replacement, and harnesses are not cheap, there are better ways.

But rather than spending $$$ to replace that... that 50 cent additional ground wire works realllllll good... if it was me.