Yesterday in upstate SC we had a little snow/sleet, but the temperatures hung out anywhere from 28-31 all day. My truck sat at work from 11am-6pm and when I went to crank it, it would turn over but never fire. After like 2-3 seconds of turning over, the turnover sound changed to a "dryer" sound, and that's when I could tell it wasn't going to crank. I plugged it up for an hour, tried it again and it cranked right up. But I have always been ridiculed by friends for plugging it up in our "mild" winters, but if that's all it takes to keep it from cranking, then how do other people around here make it with the '05+ models that don't come with them from the factory? I don't care what people say, even if it's only going to get down in the 40's I still plug it up because it runs SOOO much better when I do. If I don't plug it up and try and run high-idle right off the bat, the truck sounds like it's about to start choking out. But could I have an issue if my truck wouldn't crank at temps in the high 20s and low 30s?

 

Sounds like your 6.0L PS may have issues!

Good Batteries, glow plugs, FICM, injectors, a little anti gel to the fuel and it should start easily to -10F without plugging. Here in northern IL when I'm at home I plug in my '05 6.0L PS at +20 F and below simply because its easier on the engine as you pointed out. Should not be a problem at all with the temps you mentioned even without plugging in.

Do you know whether your FICM has the original flash or could it have been flashed with the inductive heat feature when you brought it in for maintence at some point? The inductive heat flash has been know to cause problems with the FICM which have soldering problems on the internal 48V converter board? Could be glow plug operation issues also.

 

Thanks for the info. Do you know of any ways to find this out without taking it to the stealership?

 

There are many ways to load test your batteries, one of the easiest is to take it into one of the shop and have them load test them. Rough check that I use myself using a basic DVM is to connect the DVM to either battery. Then during the following steps observe and record the battery voltage:

1) battery voltage cold after setting all night NO load => 12.4V;
2) turn on the ignition to start glow plugs(but before the light goes
out) =>11.4V; ( a drop in voltage is a good indication that some glow plugs are
working)
3) after glow plugs go off measure while cranking engine but before the
engine starts => 10.6V;
4) for the first min or so after engine starts but before the alternator kicks
on => 12.0 and slowly recovering back to the original 12.4V
5) after alternator kicks in => 14.2 in cold temperatures.

Among several vehicles I've check in this manner both the Alternator and batteries have been in good condition providing readings very close to what I've indicated. If the readings are lower then indicated, I would have the bartteries load tested. Many shops will do it for free. If the batteries need to be replaced (replace in pairs), from personal experience I would recommend either the Walmart Everstart MAXX if on a budget or if only the best is your style then one of the AGM batteries i.e. Sears AGM Diehard Platinum P2.

If you believe your problem is with your FICM, I would refer you to link:
https://www.ford-trucks.com/forums/8...procedure.html
and also TSB 09-24-3, TSB 08-26-3, TSB 07-5-4 and TSB 04-18-6 which will give you a little history on the FICM problem. You can find the TSB links on this web site or I could email them to you.

Glow plugs can be roughly but easily checked if you have a clamp on current probe (one that can measure DC amps 200 and greater). This would clamp around only the smaller red wire which connects to the passenger battery pos terminal. Have an assistant turn the ignition key to start the glow plugs but don't crank the engine. The inital current will be around 190 amps, if there is any significant difference (lower) there maybe be bad glow plugs depending on how low the current reading is.

Injectors other then adding regular additives to the fuel (i.e. power service, Earls or your favorite choice) are best left up to the shops.

Hope this helps.