components of glow plug system - Ford Powerstroke Diesel Forum
Powerstroke.org is the premier Diesel Truck Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 10-15-2012, 08:56 AM
Compression Ignition Addict
 

Join Date: Jan 2009
Posts: 196
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
components of glow plug system

Howdy, I'm curious if someone can help me continue to track down my glow plug problem. Since I've owned this truck (4 yrs now), it fries 4-6 plugs / year. I have replaced the controller twice, the valve cover wiring harnesses, and now the external harness plugs (what plugs into the wiring harness).

Not sure if it's related, but I also have an intermittent low voltage issue. I suspect that the plugs may be getting stuck on, thus lowering available voltage and burning the plugs out.

Assuming the controller is working properly, what tells the plugs to cycle on / stay on? is there something that might be causing the system to stick on and burn the plugs out?

FWIW, I use motorcraft plugs, so no autolite issues here.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2  
Old 10-15-2012, 09:25 AM
Compression Ignition Addict
 

Join Date: Aug 2008
Location: Madison, WI
Posts: 2,867
Thanks: 2
Thanked 54 Times in 52 Posts
Feedback Score: 0 reviews
There is no "controller", except for the PCM. It cycles the glow plugs for anywhere from about 30 seconds to two minutes. There are a couple of ways that the relay could malfunction and run the glow plugs continuously.

Maybe it's the relay you've replaced so many times? Are you sure you've gotten a glow plug relay, one that is NOT grounded through the mounting base like a starter relay is? What brand of relay is it?

Is it the same glow plugs (in the same positions) that fry every time?

One way to test to see if your low voltage issue is glow-plug-related -- next time it happens, disconnect the big terminal on the relay that leads to the plugs. Be VERY careful, as this terminal may be energized at the time; DON'T let your wrench touch any metal part of the truck. If the voltage returns to normal when you disconnect it, then the plugs/relay/wiring are suspect.
Reply With Quote Quick reply to this message
  #3  
Old 10-20-2012, 06:49 PM
Compression Ignition Addict
 

Join Date: Jan 2009
Posts: 196
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
The controller is a glow plug controller, not a starter relay. Thanks for the info on the PCM.

I hooked up an in-cab led to the glow plug controller so I could see when it's on. Doesn't appear to be sticking on.

I'm off on a 1200 mile trip tomorrow, so that will give me plenty of opportunity to see.

I am seeing some fairly significant voltage drop at the fuse box in the cab. For example, alternator puts out 14.5, I get about 14 at the batteries, then only about 12.5 at the fuse panel in the cab. Drops to 12 when I turn the headlights on. Is that normal or am I experiencing too much voltage loss?

Thanks!
Reply With Quote Quick reply to this message
  #4  
Old 10-20-2012, 07:10 PM
Compression Ignition Addict
 

Join Date: Oct 2011
Location: Dover
Posts: 1,618
Thanks: 1
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Not normal to me. Battery voltage should be the same through out the vehicle [bold] IF[/bold] it is suppose to be bat voltage. I think the fuse box should be bat voltage. Hopefully another member can agree or disagree with that.

This is an OBS right? If so, it has a glow plug relay, not a controller.
Reply With Quote Quick reply to this message
  #5  
Old 10-20-2012, 07:16 PM
Compression Ignition Addict
 

Join Date: Jan 2009
Posts: 196
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Yeah, sorry, glow plug relay (not controller). It is an OBS. Do you know where that fuse panel in the cab is grounded? One guess is I have a loose / bad ground coming off that panel.
Reply With Quote Quick reply to this message
  #6  
Old 10-20-2012, 07:22 PM
Compression Ignition Addict
 

Join Date: Oct 2011
Location: Dover
Posts: 1,618
Thanks: 1
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
I am not well versed on OBS trucks.

Are you familar with checking voltage drop?
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Ford Powerstroke Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -8. The time now is 09:00 AM.


Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.1
Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.

vB.Sponsors