Keith Browning Posted September 4, 2013 Share Posted September 4, 2013 We recently had a 2003 F550 in with the instrument cluster acting up - when the truck was @ idle the tach would stop working along with the right side gages, the check engine light and the battery light comes on. Raising the RPM's above 2500 made it all start working again. There was just two DTC's and they were networks codes. Disconnecting the alternator made everything work. When all of this happens the alternator stops charging. First it got a new alternator as per the WSM, next a new cluster. No joy there. A known good test PCM was glugged in. Still no joy. I played around with the FICM and engine harnesses suspecting RFI could be an issue. Paying attention to where the engine harness is close to the injector harness I separated them as best I could. Ah ha! That did not fix it however now you have to get the RPM's over 3000 to make the cluster and charging system to stop working not to mention a loud buzzing through the radio that wasn't there before. I plugged in a known good test FICM and verified the FICM harness ground was good. Then I replaced the FICM. Oh joy! So would I be wrong in assessing the FICM was causing this through the harnesses? This was a strange one to figure out. Quote Link to comment Share on other sites More sharing options...
lmorris Posted September 5, 2013 Share Posted September 5, 2013 What about ground straps? Wasn't there a recall on the early 6L for the ground strap being loose at the block and messing up the suppression strap on the right head? Quote Link to comment Share on other sites More sharing options...
cbriggs Posted September 8, 2013 Share Posted September 8, 2013 The ground bolt on the lower rf of the engines weren't tightened enough, some loosened off and then would overload the body to engine groundstrap and burn it off during cranking. Quote Link to comment Share on other sites More sharing options...
Aaron Posted September 8, 2013 Share Posted September 8, 2013 I have seen a truck that someone forgot to re attach the ground when they changed trans cooler lines, was at my shop for intermittent no start. It was starting off the ground strap, which had burned through the heater box when it was glowing red and eventually melted off. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted September 8, 2013 Author Share Posted September 8, 2013 What about ground straps? Wasn't there a recall on the early 6L for the ground strap being loose at the block and messing up the suppression strap on the right head? As I recall that was 7.3L engines. Quote Link to comment Share on other sites More sharing options...
Brad Clayton Posted September 8, 2013 Share Posted September 8, 2013 ATTACHMENT III Safety Recall 04S15 Certain 2003 Model Year F-Super Duty and Excursion Vehicles Equipped With 6.0L Diesel Engine - Negative Battery Terminal to Engine Block Connection Technical Information SERVICE PROCEDURE Raise and support the vehicle on a hoist. Locate the battery ground cable stud bolt at the right front corner of the engine block. See Figure 1. Grasp the ground cable assembly by hand and determine if it is loose at the block. Figure 1 Remove the positive battery cable bracket from the stud bolt. Remove the ground cable stud bolt from the engine block and discard. Inspect for evidence of arcing or carbon buildup on the ground cable eyelet terminal. Clean as necessary. To ensure a good ground path, use a wire brush or equivalent to clean the engine block surface and ground cable mating surfaces. Install the new ground stud bolt. Tighten it to 62.5 Nm (46 lb-ft). Install the positive battery cable bracket to the stud bolt. Tighten it to 30 Nm (22 lb-ft). Grasp the ground cable assembly by hand and make sure it is tight at the engine connection. Lower the hoist.NOTE: The following steps are only required if the battery ground cable was found loose in Step 2. Open the hood and locate the radio suppression strap near the right rear corner of the engine compartment. Inspect the suppression strap for signs of heat damage from increased amperage flow due to the loose ground connection at the engine block. If no damage is found, close the hood and release the vehicle. If the suppression strap shows signs of heat damage, inspect the surrounding components for similar damage. Repair as necessary. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted September 8, 2013 Author Share Posted September 8, 2013 I stand corrected! How did you find that by the way? I looked but... Quote Link to comment Share on other sites More sharing options...
Brad Clayton Posted September 8, 2013 Share Posted September 8, 2013 Google Quote Link to comment Share on other sites More sharing options...
lmorris Posted September 9, 2013 Share Posted September 9, 2013 What about ground straps? Wasn't there a recall on the early 6L for the ground strap being loose at the block and messing up the suppression strap on the right head? As I recall that was 7.3L engines. I do recall some issues with the 7.3L having loose ground straps, mainly because the nut for the trans line bracket would be crazy tight and it would try to spin out the bolt as well. Quote Link to comment Share on other sites More sharing options...
DieselD Posted September 10, 2013 Share Posted September 10, 2013 I have had the 6.0 loose block ground cook off the ground strap and melt through the heater boxes as well. Also I have had loose battery cables cause some wierd shit. One that kicked my ass for a long time was a F750 with a 6.0. It had the symtoms of a dead ficm(no injector pre cycle etc) I replaced it and it fired right up. During my roadtest it left me stranded but after I had it towed back to the shop it was ok again. I couldnt duplicate it for several days. Long story short I could unbolt the ficm and move it around to get it to start, even got sparking between the module and engine brackets. This happened with both old and new ficm so it couldnt be a internal issue with the module. I took a break from it for a day and came back with a fresh head and started over. Ended up having a loose ground cable at the batterys which I missed. tighted it up and all was well. This was the truck and yes this is how I had to work on it. I pulled the hood off it at one point to do coolers but it was a giant pain in the ass. I ended up working around it during my ficm fiasco. Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted September 13, 2013 Share Posted September 13, 2013 Google g O 0 G L E is your friend...... Quote Link to comment Share on other sites More sharing options...
Aaron Posted September 14, 2013 Share Posted September 14, 2013 http://bit.ly/17WzJqB Nothing negatives is meant by this but I just find this site hilarious whenever google is brought up. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.