Hard/no start replaced glow plugs, harnesses, gpcm

[darrenvalente@gmail.com]

I have looked and looked, but I'm just not seeing a solution. I bought a 2006 6.0 in Florida in august. Now that it is getting cold here in Michigan it doesn't want to start on cold mornings. After the glow plugs cycle, and I begin to crank the batteries will die within seconds. If it does start, theres more white smoke than my old AutoCar with 500,000 miles, and runs very rough. After it's started for the first time in the morning, it starts fine all day.
So here's where I'm:
Both batteries load test great multiple times.
Alternator test good.
48.9v at FICM
I replaced the GPCM, all glow plugs, and glow plug harnesses. I figured at 106k it wouldn't hurt plus I was positive the problem would have been one of those.
Also when in neutral, at high rpm I get a lot of white smoke. Haven't really seen that under load.

I've had lot's of 7.3s, none with these problems...

[southend]

Do you have a monitor, to check battery voltage, ficm while running/cranking, and pull codes?

Sent from my phone that somebody didn't help me get.

[rowcoach]

Replace the batteries. They should not be running down during start up. As said above get a monitor to see voltages during start up.

[dannyboy950]

If your batts load tested good and are still quickly drew down you have a shot in the starter or the wireing going to the starter. Only thing that can draw down hot good batteries that quickly.

[southend]

Originally Posted by dannyboy950

If your batts load tested good and are still quickly drew down you have a shot in the starter or the wireing going to the starter. Only thing that can draw down hot good batteries that quickly.

I agree, bum starter or cables.

Sent from my phone that somebody didn't help me get.

[darrenvalente@gmail.com]

Does that make sense, if it happens only in the morning?

[ejg3855]

Originally Posted by darrenvalente@gmail.com

Does that make sense, if it happens only in the morning?

I been fighting a similar issue, have a thread. I am waiting for glowplug harnesses should be here tomorrow so I can get back to diagnosing.

2 x New Batts
Gp's and Harnesses
IPC switch and wiring harness
Oil Change with Rev-X


So far has been my attack plan.

[dannyboy950]

In the morning you are adding the start up of the glow plug sequence to your power drain which is why it is more noticeable. The glow plugs can draw up to 300 amps I have often seen while testing.

This is all assumeing that the batteries have load tested good each individually. A volt test is not enough in this situation you can have 13.5 volts but only 10 amps avilable and that ain't enough.

[darrenvalente@gmail.com]

Well Row Coach was right!
I tested the batts with both a digital and manual tester, both at my shop and the parts house they both indicated good.
After spending about $450 on glow plug system, decided to try the batts for the hell of it.
Eureka!
My advise, if the batts are more than 2 years old just replace them. Mine were about 2.5 year old 750 cca Motorcraft.

[rowcoach]

Glad you got it fixed. Sorry you spent all that money on good parts.