Glow Plug Issue
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Laughing Gas
Joined: Apr 2011
Posts: 1,002
Likes: 7
From: London, KY
Glow Plug Issue
Glow plugs not working. No check engine light. Pull the codes, getting a code for 6 glow plugs. Can't remember which two I'm not getting a code for. I was getting a P0683 code for the module too so I replaced the module and I'm not getting that code anymore. Still getting codes for 6 glow plugs. You guys think I have 6 bad glow plugs or bad glow plug harnesses or both?
Tuned
Joined: Oct 2003
Posts: 491
Likes: 0
From: Tampa, FL
From what I've read, the only way to properly diagnosis a glow plug problem is to disconnect the harness and check the resistance of each glow plug with a digital volt meter. Be advised however that it seems that just the act of disconnecting the glow plug harness frequently results in its damage, necessitating replacement. My take is that if you decide to attempt the diagnosis outlined above you should be prepared to replace the harness or harnesses that you disconnect so you don't find yourself stuck with no parts to get the truck up and running again.
I don't have the specs handy for what the glow plugs should show for resistance, but a quick search on this site will certainly pull them up.
I don't have the specs handy for what the glow plugs should show for resistance, but a quick search on this site will certainly pull them up.
Fleet Owner
Joined: Apr 2012
Posts: 27,307
Likes: 549
From: Spanaway
You don’t have to remove the plug end. Just take the reading from the plug
with glow plug in circuit. If you find some thing out of range then you know
that you may want to get harness and plugs. I can post a pin point testing PDF
later today after I get home.
with glow plug in circuit. If you find some thing out of range then you know
that you may want to get harness and plugs. I can post a pin point testing PDF
later today after I get home.
Elder User
Joined: Dec 2000
Posts: 808
Likes: 3
Here's a link you can view. Both 7.3 and 6.0 is described here. The info on the 6.0 is at the 11:50 mark. I checked all four and sure enough, #2 was wayyyy out of range. I'll be replacing all 4 since I'm in there. And yes, like what has been mentioned. Pick up a harness in case you break it. I did the passenger side a few years back and I broke the harness when I removed it. I had bought one just in case. Well, I needed it and glad I had it.
Eddy
Tuned
Joined: Oct 2003
Posts: 491
Likes: 0
From: Tampa, FL
Just for future reference, what is the group's consensus on utilizing aftermarket glow plug harnesses. Although being in the industry I totally understand the value of using OEM parts and the issues involving quality that may arise with aftermarket parts, these harnesses are just wires and terminals and I've seen huge differences in pricing between the MC parts and aftermarket alternatives.
Just something I was thinking about when I stumbled upon the price differences and I'm curious.
Just something I was thinking about when I stumbled upon the price differences and I'm curious.
Laughing Gas
Joined: Dec 2017
Posts: 846
Likes: 34
How about non-factory glow plugs? While it's open, I wonder should I replace them all. Since this is a replace but it's not broken, I dont' want to shed too much money. One is $10, but 80 is $80, then the harnesses, around $35 I think. The point is spending $80 is not a problem, but spending unnecessarily $80 is rather not very smart right?
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Fleet Owner
Joined: Apr 2012
Posts: 27,307
Likes: 549
From: Spanaway
Glow plugs are one of the few things that I do say "while you in there".
They are sort of like a light bulb in that they age over time. Plus it sucks
to have to go back a few weeks later for just 1. They never are in the easy spot.
They are sort of like a light bulb in that they age over time. Plus it sucks
to have to go back a few weeks later for just 1. They never are in the easy spot.
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Fleet Mechanic
Joined: Nov 2016
Posts: 1,343
Likes: 94
My experience on aftermarket harness options. I thought how can they screw up a harness, so purchased one from Oreilly. Dealer was closed.
Threw in new glow plugs attached the harness, went to plug it into the wiring harness and danged if it would not clip together. The depth of the female vs male connectors didn’t match, so I would need to start trimming the plugs to get a connection.
Waited till dealer opened, new OEM harness plugged together perfectly.
Threw in new glow plugs attached the harness, went to plug it into the wiring harness and danged if it would not clip together. The depth of the female vs male connectors didn’t match, so I would need to start trimming the plugs to get a connection.
Waited till dealer opened, new OEM harness plugged together perfectly.
Fleet Owner
Joined: Apr 2012
Posts: 27,307
Likes: 549
From: Spanaway
My experience on aftermarket harness options. I thought how can they screw up a harness, so purchased one from Oreilly. Dealer was closed.
Threw in new glow plugs attached the harness, went to plug it into the wiring harness and danged if it would not clip together. The depth of the female vs male connectors didn’t match, so I would need to start trimming the plugs to get a connection.
Waited till dealer opened, new OEM harness plugged together perfectly.
Threw in new glow plugs attached the harness, went to plug it into the wiring harness and danged if it would not clip together. The depth of the female vs male connectors didn’t match, so I would need to start trimming the plugs to get a connection.
Waited till dealer opened, new OEM harness plugged together perfectly.
Senior User
Joined: Sep 2016
Posts: 146
Likes: 0
From: Skowhegan, Me.
I have a issue now, I went to start my truck this morning, no GP light,it started fine...it was 25 degrees out. I called the dealer. Guy said it may be because of a tad warmer weather. I dont buy that as it comes on during the summer. I do have the check engine light,but I had that scanned and cleared the other day, and it pointed to the mass air flow sensor.
Fleet Owner
Joined: Apr 2012
Posts: 27,307
Likes: 549
From: Spanaway
What truck are you working on? Your sig has a 2014 and not a 6.0L.
This thread is for a 6.0L engine.
You might check the EBP sensor wire to see if it has any damage right near
the connector. You would be shocked at all that will screw with if chaffed and
contacting the other wires is happening. Use a good magnifying glass and take
a careful close look.
Also on not getting the WAIT TO START light. Did the dash light come on
during the prove out pre-start when all the lights should come on?
If not you could just have a bad lamp
This thread is for a 6.0L engine.
You might check the EBP sensor wire to see if it has any damage right near
the connector. You would be shocked at all that will screw with if chaffed and
contacting the other wires is happening. Use a good magnifying glass and take
a careful close look.
Also on not getting the WAIT TO START light. Did the dash light come on
during the prove out pre-start when all the lights should come on?
If not you could just have a bad lamp