just curious, cause i am going to do this fix as well. but did you ADD another resistor, or just resolder?? thanks

 

I added a 10k resistor. I may pull things apart and replace the 10k version with a 20k version, though. I am also likely to upgrade my capacitors at the same time. Not much sense in tempting fate. Asking the capacitors to operate at above their designed voltage sure seems like you are pushing for their early demise, thus leaving you stuck on the side of the road. It's just not worth the risk, IMHO.

I will share that doing this procedure with a $15 soldering iron is a quick ticket to potentially hurting stuff. I have a digitally controlled soldering station that regulates tip temperature. You don't want to have to dwell too long on any of the connections to get the solder to reflow, but don't want to have such a high temperature that you damage the components. It's all about using the right tips at the right temperatures.

 

(with the right flux)

 

How is the compared to the swamps, besidesthe of voltage

 

No one that I know of has published what, precisely, Swamps does to the units he receives. Following the repair of the unit in my Excursion, I have begun offering the repair of these units for folks not set up for or interested in doing it themselves. I have been doing upgrades as requested. Swamps certainly has a good product, though. No doubt.

 

Oh really... this diesel newbie just blew a second FICM. Maybe I shouldn't mudbog as hard as I do. Was tempted to do it myself, but I might be interested in hiring someone to do it for me if the price is right. More info would be appreciated! (DunnJH4@Gmail.com). Tell me a little more about the upgrades too.

 

Just an update - I did indeed pull out my FICM and replace those capacitors. All electronics looked fine when I pulled it apart, I just didn't want to tempt fate as I have seen some fried ones on other units that some friends of mine dropped off to me (when the two brought to me had fried, they took part of the printed circuit board with them - bummer). Given that I upgraded to capacitors capable of more than the 58V that it was outputting, I opted to leave the 58V mod in.

Upshot: I wouldn't recommend upgrading to 58 volts without changing out all the capacitors unless you want to roll the dice on your PCB and roll them further on getting stranded.

 

Just fixed mine with Dr. Quad's most excellent advise. Other electrical problems I have been having are also fixed. My driver side window was slow and herky jerky to roll up, My CD player quit working, the truck generally ran rough. After the fix the window works works well, the CD player works and the truck starts faster and runs much smoother. Not sure why the FICM fix helped the other problems since the dealership said my electrical problems have nothing to do with the low voltage (24 volts) on the FICM. Thanks Dr. Quad you saved me $1200.00.

 

Another update - my FICM is now fried. I do not believe that replacing the capacitors with versions that have a higher microfarad rating as is suggested in pstrang's writeup is a good way to go - at least not without changing out the FET's and perhaps other components as well.

Everything, for thousands of miles actually, was fine with the voltage upgrade alone. The issue occured after the caps were replaced.

Of potential significance, however, is that I had never towed any considerable distance since doing the original repair. When the unit died, it did so when I was pulling an 8800# travel trailer.

 

What were the specs on the caps you used as far as voltage rating, temperature rating, etc?

 

Like most 4 screw FICM’s, mine had OEM input caps rated at 35V, 1000µF, 125ºC. The OEM output caps were rated at 50V, 470µF, 125ºC. The replacement caps that I ‘upgraded’ to on the input side were 35V, 1800µF, 105ºC. The replacement output caps were 63V, 680µF, 105ºC.

My guess is that the power FETS and .0075ohm resistors simply cannot handle supplying the necessary power to fill the caps without overheating.

I have seen a similar issue on a 7 screw FICM, where all eight of the OEM caps were 63V, 330µF, 125ºC, but had been replaced with those same 63V, 680µF, 105ºC caps only to have the unit later fry.

When my unit died, it did so after towing 30 miles of somewhat steep rolling hills with more downshifting than would typically be encountered in daily driving. My guess is that this created the extra heat that the components ultimately could not handle.

I am currently working to locate replacement input and output caps that more closely match the OEM specs while sticking with the same OEM dimensions. The OE caps that I have been seeing generally test out at 303-306µF. It would be nice to have the option of replacing them with non-degraded versions.

The trouble is that once a board fries, it is no simple matter. You have to replace the board. Some have gotten lucky and found only a resistor popped off the board. When the units fail catestrophically like this, though, you are generally stuck getting a new board.

Situations like this are the basis of my continued search for a bench test procedure. I want to be able to run the unit HARD on the bench instead of trying my proverbial luck on the road.

 

Clarification - 330µF OE caps have been coming at the 303-306µF. The 470µF caps have been coming in around 440µF or so. The 1000µF ones have been mostly in the 990-1010µF range.

Only one capacitor out of the last 30 units that I have seen has been completely shot.

 

Thanks for all the great info on bad ficm's I tested mine today and found that it was only putting out 30v while runnning and 28v while cranking. I took it out and did the soilder fix on it. I didn't try to soilder the resistors because they are to small to get the soilder gun that i have in there to do it and the size of the soilder points scared me away a little. I reinstalled it and tested again and now I'm getting 48v key on engine off and 38v cranking and running. The ? is should I redo the cap soilder points or do i need to do the resistors. Also there are some referbished ficm's on e-bay for 200$ ish has any one used these. Just trying the make the decision to try to fix mine again or send it out to have someone who has knows what they are doing fix it before i hose it up.

 

Would somebody email me the PDF of this please (rep will be given)

SuperBikeCJ@gmail.com

 

sent ya what I have ....