Glow Plug Testing?? Dunno

[Jacup84]

I have been loooking and searching around on a sinmple thing. How do you test your glow plug once it's out of the truck. All i find is 7.3 videos and stuff which has the plugs but none for the 6.0 i have a multimeter just need to know where to set it and put it to check or if it's even possible.. I got a code saying #2 glow plug was bad to changed it still have code after i cleared it so I just want to check old one and the others while i am at it thanks.

[m-chan68]

Set your DVOM to OHMS. Touch the red lead of your DVOM to the end of the glow plug where the electrical connector plugs into (not the end that sits inside the combustion chamber), and touch the black lead to the threaded part of the glow plug. You should obtain a reading of between 0.5 to 2.0 ohms on a "good" glow plug. Any higher than that, replace it. Also plan on replacing the glow plug harnesses too, since removal of them pretty much mandates replacement.

[Jacup84]

Ok i did that and on my SCT and my CTS insight it comes up code p0672 i replaced number 2 glow plugnow that i test it shows it's good even with new plug code still appears

[m-chan68]

Okay, then the next step is to unplug the black connector plug (not the green one) from the glow plug controller on top of the passenger side valve cover. Look for a pink with light green stripe coloured wire in that connector. Use your DVOM with the red lead touching that cavity and the black lead touching your passenger side battery negative terminal. If you are still getting readings within 0.5 to 2.0 ohms, replace the GPCM.

[Jacup84]

ok it shows .8 just like the new plug and old one. so my gpm is bad and if so would it just show up 1 gp bad

[m-chan68]

I have had more than my share of trucks flagging specific cylinder/circuit(s) faulty that ended up needing new GPCMs. If you are in doubt, "borrow" a known good GPCM from another truck, and re-run a self-test. By ohming out the circuit directly from the GPCM to the battery, you have eliminated the wiring from the GPCM all the way to the glow plug, leaving the GPCM the only possible component left to set the DTC.

[Jacup84]

Thanks man for the quick replys i will do that i have a good friend with one to try that one.

[babs2972]

I would love to know how in the world you even got your glow plugs out in the first place?! I looked at my 05 today and think this is near impossible.

[SDER1]

Attempting to replace all of mine today without tearing up the harness as everyone says is probable. Going to run to get gas for the last cut of grass, then attempting it with the engine warm for the o-rings in the harness. Hopefully I won't tear anything up on a Holiday, but the cold spell is coming in tonight.

Open to suggestions/good practices. Posted on another forum solicitating the same, last night.
-Will

[SDER1]

Forgot to add, I have a 2006 F350 with 139k on the mileage... thought I had my signature on this one.