Just completed oil cooler and egr cooler replacement on my 2006 6.0. When restarted engine after these repairs battery light came on let engine run for about 5 minutes shut it off then restarted it and both battery and check engine light came on. Drove truck about 24 miles like this, shut it off and it would not restart batteries dead. Charged both batteries and load tested them both checked ok, put them back in truck and it fired right up but battery light was on, shut it off restarted and once again battery and check engine light came on, put a code reader on it and all 8 glow plugs showed failure. Drove it 12 miles home and battery light went out but check engine light remained on, drove it about another 24 miles with out shutting it off truck runs fantastic, shut it off and it barely would restart batteries low again Have replaced ALT. (it showed 14.5 volts output) positive battery cable, load tested both batteries. Everything tested good. Now since I am getting an error saying all 8 glow plugs failed, mean that maybe the glow plug control module /relay on passenger side valve cover is bad and draining the batteries, while truck is running. I checked both batteries while connected and truck turned off and they both stayed at almost 13 volts with out dropping,so I do not think the drain is occurring while truck is shut off ( No dead shorts) only when it is running! Any suggestions, Anybody

 

Welcome, first I would make sure you got all of the wiring connections seated well. I'm guessing you didn't have problems with the glow plugs before the tear down, so maybe some dirt/grime made it way into a connector and make sure the glow plug relay is seated as well. Could be a bare wire in the area of the glow plug relay from the recent work also.

 

Hey thanks for the reply. And no had no glow plug issues before the tear down. cleaned all plug connections with a vacum, did not want to use compressed air thought might damage internals of the smaller wiring connections, when reassembling but tried the vacum to suck up any debris that might have fallen in connectors. Have went back through and cleaned as many connections as I can reach without tearing the top of the engine off again. One thing I did learn is that when you replace the oil cooler be sure to keep the high pressure reservoir clean and do not let any filth get into the HPOP or you will have to replace the IPR sensor/valve, lint from rags used to clean that area up plugged that little IPR up tight, truck started died and would not start again until IPR was replaced, but must state again the truck runs like brand new now, once you charge the batteries !

 

I agree check things Over

Follow the Ground Cables to Frame and Engine clean the mounts/cables

Is the Main Positive cable coming off the Alternator got good connection


Scan the DTC most auto parts store do it for free

 

Yes don't use Rags to clean

I use compressed air it wont Hurt any wires cleans Good

Keep an Eye on ICP if it spikes High ICp then the IPR Screen could be Plugging again

 

where did you buy the New Alternator AT

 

Thanks for the reply! Bought new alt at Oreilly auto parts. Haven't checked ground to block will do that today, main cable to ALT is connected firmly and both ends and at battery the positive cable is brand new so no corrosion there (good solid connection)going to try ohm checking it today with volt/ohm meter. Still just wonder if that control module for the glow plugs didn't flip out since scan came up with all 8 glow plugs failing, I read that the glow plugs draw a lot of juice and we unplugged that module during the rebuild, I pulled it out again and checked that no pins were bent and cleaned the connections but just wonder if something internal didn't short out and glow plugs are like stuck on all the time?

 

I was even to beginning to wonder if it isn't a wire chaffing problem, read a little about it in another post, but kind of discounted that, because that guy had problems more related to rough idle, stammering during acceleration, truck just shut down while running down the road, stuff like that, For now I am just checking the basics, it's usually the simplest and most obvious that gets you on something like this, that is why I replaced the positive cable harness it was corroded real bad on passenger side going down to the starter and have had corroded cables give me fits on an old bulldozer one time.

 

Hey, jswartz84 and BLADE35, FIXED IT drivers side ground cable to frame was loose and showed signs of arcing to frame (all black and charred) battery light is OFF and my little scan gauge is back to reading 12.1 to 12.5V while running down the road, it was reading 11.0 to 11.5 when battery light was on. THANKS for your suggestions just needed someone to get me focused back on the basics instead thinking something catastrophic and high tech had went wrong! THANKS AGAIN!

 

Glad it worked out for you I had a feeling since it just had a overhaul thanks for the Update


That New Alternator don't sound to strong

or theres More Loose Connections Look into the Glow Plug Connects since it sounds like you had a DTC for that

Does it come up to higher voltage after a couple minutes??



Smear Vasiline on All those electrical connects works great

 

Good call Benny.
Lancer09, if possible keep an eye on your ficm voltages now that stressed it. Glad you found the problem.

 

Yea I have what I think is called dielectric grease that I put on all electrical connections to keep corrosion at bay and promotes a good electrical connection. Thanks again guys for your help.

 

Hey, jswartz84 or BLADE35. Its me again you were right, there is still something wrong with the old 6.0 voltages at batteries started to drop again, checked ficm voltages, cold key on 47.8, cold key on while pump is buzzing 47.1, cold while cranking 48.1 so think ficm is ok. When you measure batteries cold, key off are in the 12 to 12.5 volts start the truck no assces. on running at 2,000 rpm voltages drop to upper 11 volts let off the gas and volts get into the lower 12 volts ran truck 5 min from cold to see if it was because of glow plugs still on but the same after 5 min of running. installed new ALT (still have all 8 glow plugs showing fault with code scanner,)but battery light did go off once new ALT was installed, but battery voltage keeps getting lower everytime truck is run. Started out key off voltages around 12.5 truck has been driven a couple of times and now key off voltages at batteries are around 11.9 to 12.01 volts. Any more ideas, all grounds cleaned and good, new positive cable, put two known good batteries from my truck in and still only got 12.3 volts at batteries while truck running at 2,000 RPM no assces. on.

 

Could it be a broken wire harness down at the glow plugs, cause I was under there during the repair, took both up pipes off the exhaust manifold, and pulled Y pipe out the top, maybe broke a glow plug wire while I was under there thrashing around with my tools? that might explain the glow plug codes but would it have an effect on batteries not charging?

 

Well what DTC

Has that DTC ever been turned Off and if so When



Whats this about the voltage drop at 2000 RPM does this happen always Does the Battery Light come On during this??



Almost sounds like the Glow Plugs are getting stuck on


Does Battery only run Down Engine ON??
Do you have a DVM