okay, I plug the block heater in every night. well, every night it is below 50, it just runs better if I do.

so, this year, its been fine, but when it got cold, 20s and lower, it would not start. the glow plug indicator light on the dash stays on, like the heater was never plugged in.
have to charge the battery to get it started. not just jump it, but charge.

if I leave a charge on the battery all night, AND the heater plugged in, it starts fine. but I have to do BOTH.

batteries, alternator, starter, all checked out fine at my local car parts store.

any ideas!!???

 

check the block heater for a bare spot on the wire near the plug. It shouldn't affect anything else, just a wire to the element and back. You can ohm it out with a meter, about 10ohm Resistance.

Glow plug light doesn't go out... try cycling the key a couple times... let it run a minute or so, and try again. Check the truck for codes. Verify the glow plug controller is plugged in for tight connections, in right near the passenger valve cover, up front.

 

Get those batteries charged up, what CCA are they? My 900s crank in 20f degree weather normal. As for block heater cable, ohm the heater to make sure it works. New cable is 15$ on Amazon(just got one). There is also a write up somewhere about ohming the glow plugs maybe someone will help out with that

 

The low voltage may be killing your FICM

 

thanks so much everyone! I will check all this out. I really appreciate the suggestions! I will post back ASAP when I have the answer, or when I do not, either way! thanks again!

 

Definitely something not right. My 05 fired right up in 20F weather up in the mountains without being plugged in. Glow plug light was on for about 10-15 seconds.

Typically a bad glow plug will throw a check engine light.

 

the more my husband and I read on this, the more it appears to be the FICM. I think it has been a problem for a long time as I always need to have it plugged into the heater if the night temps drop below 50 in order to have a good start.
that being said, any suggestions on replacing this? found a good price for a whole unit at All Computer Resource, among some others. anything I should watch out for, should I get the upgrade? (I tow a 33' horse trailer with living quarters, 10k lbs +-)

 

What is the ECT with KOEO after being plugged in all night?
What is the supply voltage (12v side) to the FICM?
What is the FICM output voltage?
You can get a cheap BT adapter and Torque Pro app to read all of these things which will help avoid making any assumptions and wasting money on unnecessary parts.
You will also want to look at ICP and IPR while cranking.
If I ever have a FICM issue I will use FICMRepair.com and get the lifetime rebuild and Atlas 40 tune.
You may not want the Atlas 40 if you are towing heavy with stock exhaust and no EGT gauge or if you have a tuner.

 

do you have anything to read live data, like a scan gauge II or Torque Pro app for Android phone? FICM's cost big bucks... I'd confirm its the issue before spending the money and a live reading device is a good investment for trouble shooting these issues. You'll need to program the scan gauge or buy a pre-programmed one specifically for diesel 6.0 data. Called X-gauges, good video on you tube for doing this. Advance Auto sells the Scan Gauge II for $159, TRT30 for a coupon code, by on-line and do in-store pick-up. Program it and see for yourself if it's really the issue and of course, lots of other things the truck is doing before its to late.

You could send the FICM to FICMrepair.com and Ed will take good care of it. He has an exchange program, you buy his and pay the core, he refunds the deposit when you return a re-buildable core. that would eliminate the down time, easy to replace.

But buy the sounds of it, may very well be the issue. To confirm it, don't plug in the block heater and heat the FICM (drivers side above the valve cover) with a hair dryer. If it starts easy, most likely your issue.

FICM's die by weak batteries and weak alternators, I'd have both checked ASAP or risk roasting the new one if that's what's needed.

 

I saw this and I was like -50°! Damn that is cold. Then I realized he didn't mean very cold.

In addition to what they have said if you have your batteries tested at a shop make sure they disconnect the batteries when they test them. Dad's 6.0 had a collapsed cell in one battery and they kept telling him the batteries were good because when they tested one they were actually testing both.

For the alternator Napa tested the alternator in my F150 three times and told me it was good. Scangauge said 12.1, so Napa's bench tester lied to me.

Do you have an additive in the fuel? Since you're call 50° very cold I'm guessing that you don't see it that often, so the fuel could be gelling.

Do you have a scangauge? Best $150-$170 bucks you can spend to get started testing everything. Watch the FMP voltage! If it ever drops below 47v then stop cranking.

 

Howdy,

Don't make any decisions on what you read or what the truck DOES except to do more diagnostics.

With a 6.0, you cannot diagnose very many problems without FIRST scanning it using either a ScanGuage, other OBD II scanner or an IDS. My 2005 starts easily and reliably in the mid teens with NO block heat at all.

Don't just charge the batteries also.....unless they're already new. Get them load tested. If they've been in the truck for a few years, and they're questionable, replace them.

Dittos! You need to know the above "stuff" before you start replacing "stuff"


Regards,


Rick

 

fuel will gel below 20*, not at 50* and normal winter diesel has added additives, will be good to 25* without adding anything extra.

 

OP did say it had been getting down in the 20s.

 

yes, we have a ScanGuage I believe. so I don't need a something like a "check engine" light? codes will be thrown even without any obvious error?


okay, this has always been a problem since I got the truck 8 yrs ago, I just thought "oh, its diesel and this is what it does when it is cold." and plugged it in. and I've changed batteries in that time! that being said, I do think the batteries are not good, and no, they were not tested properly. I didn't know!


and Ex_Limited, it gets in the 50s at night often here! not so often in low 20s and teens, that I when I was having the issue if just not starting at all, even with heater plugged in. above that, it starts fine, as long as the heater is plugged in.


it will start in the 20s and teens with a trickle charger on all night, AND the heater plugged in.


really appreciate everyone chiming in on this forum!!

 

program the scan gauge for the x-gauges you need to see. A good video on you tube by diesel tech Ron on how to do it. Then go to scan gauge web site and read about the 6.0 FORD and the gauges programming codes needed for FICM, main voltage, oil temp and coolant temp. There are about 15 gauges I use all the time, we worth the effort and WILL save you some $$$ in parts by finding the right problem.

It will store soft code or pending code without setting the light off. Scan Gauge is a bad code reader, a very good live data gauge!