Notices
1999 - 2003 7.3L Power Stroke Diesel  
Sponsored by:
Sponsored by: DP Tuner

Glowplug relay

Thread Tools
 
Search this Thread
 
Old Dec 4, 2012 | 09:39 AM
  #1  
Jimbo1977's Avatar
Jimbo1977
Thread Starter
|
New User
Joined: Aug 2012
Posts: 15
Likes: 0
Glowplug relay

I have a E99 F350 CC 4X4 LB DRW 7.3 136K Miles. My truck was taking for ever to start and blowen white smoke. After if started it ran fine, and would start with no issues. So I check the glowplug relay and I had 12.3 V on the line side. The load side I would only have 9V. I replace it with a new one from Napa (Westbay) Auto parts. Now the truck sounds like I have a dead battery when I start it. It does start, but it does this everytime I start it. I check the new glowplug relay I have 12.3 V on the line side, and 10 V on the load side when the wait to start light is on. When the wait to start light goes off the voltage on the load side goes from 10V to 11.3V. Not sure why it's barely turning over now. Is the new growplug relay I got bad too. The glowplug relay is making a loud clicking noise now too while the wait to start light is on. Any input would be great. Thanks
 
Reply
Old Dec 4, 2012 | 09:44 AM
  #2  
Papa Tiger's Avatar
Papa Tiger
Fleet Owner
10 Year Member
Community Builder
Liked
Loved
Joined: Mar 2012
Posts: 26,200
Likes: 4,151
From: Near Cal. Avenue
U probably have a weak battery. Have it and the alternator tested. A weak battery rears its head with the application of the glow plugs power draw. If it can't sustain voltage the relays begin to click. It may be so simple as corroded cable connections. Anywhere in the cables.
 
Reply
Old Dec 4, 2012 | 09:56 AM
  #3  
PaysonPSD's Avatar
PaysonPSD
Post Fiend
Joined: Nov 2007
Posts: 9,549
Likes: 14
From: Payson, AZ
The WTS light is just a timer and does not indicate if the GPR is operated or for how long.
--------------------------------------
From the Ford service manual:

The 7.3L diesel engine uses a glow plug system that preheats air in the combustion chamber to improve cold engine starting.

The system consists of:
<DIR><DIR>glow plugs.
glow plug relay.
glow plug module ( CA Trucks and Excursions)
powertrain control module (PCM).
engine oil temperature (EOT) sensor.
barometric pressure sensor (BARO sensor).

</DIR></DIR>The glow plug system is electronically controlled by the PCM. If the oil temperature is below 131°F (55°C ) the PCM will energize the glow plugs immediately after the key is placed in the ON position.

Then, depending on the readings from the engine oil temperature (EOT) sensor and the barometric pressure (BARO) sensor, the PCM determines how long the glow plugs will be on.

Glow Plugs — PCM-Controlled

The glow plugs are located in the cylinder heads, under the valve covers.
The glow plugs are self-regulating. If the engine oil temperature is above 131°F (55°C ), the PCM will bulb-check the WAIT TO START lamp but not energize the glow plug relay or control module.
The PCM system uses the glow plug module (if equipped) to conduct current to the left and right bank glow plugs.

The PCM protects the glow plugs by energizing them for short durations if the battery voltage is abnormally high.

The glow plug ON time varies from 0-120 seconds depending on battery voltage, engine oil temperature and barometric pressure.

On California vehicles the glow plug monitor (GPM) system is part of the On-Board Diagnostics II (OBD II) System.

The GPM system is designed to find failed glow plugs or failed wiring in the glow plug system.

A failure in the glow plug system will set a diagnostic trouble code (DTC).
--------------------------------------------------
 
Reply
Old Dec 4, 2012 | 10:22 AM
  #4  
Jimbo1977's Avatar
Jimbo1977
Thread Starter
|
New User
Joined: Aug 2012
Posts: 15
Likes: 0
Thanks for the info. I'll take it down and have the batterys and alt tested.
 
Reply
Old Dec 4, 2012 | 06:02 PM
  #5  
woodnthings's Avatar
woodnthings
Cargo Master
15 Year Member
Photogenic
Joined: May 2010
Posts: 3,047
Likes: 10
From: Snohomish, WA
Club FTE Silver Member

Make sure you disconnect the batteries from each other. They need to be tested individually. Take the power cable off the drivers side battery and test it, then the passengers side. Once complete hook up the drivers side or install new batteries. Most likely you have a dead cell in one of them. They BOTH need changed though.

Costco has a good price on batteries if you have one nearby.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Thinblueline50
1999 - 2016 Super Duty
1
Oct 19, 2015 10:42 AM
1L243
1999 - 2003 7.3L Power Stroke Diesel
4
Dec 31, 2011 09:04 PM
brownie83
1999 - 2003 7.3L Power Stroke Diesel
6
Oct 12, 2011 08:49 AM
No2Oil
1999 - 2003 7.3L Power Stroke Diesel
15
Feb 7, 2006 09:31 PM
roaky81
1999 - 2003 7.3L Power Stroke Diesel
4
Dec 4, 2005 01:23 AM




All times are GMT -5. The time now is 05:24 PM.

story-0
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level

Slideshow: The VelociRaptor Expedition gains a lift, upgraded suspension, Brembo brakes, and trail-ready equipment while retaining the stock 440-horsepower EcoBoost V6.

By Verdad Gallardo | 2026-06-12 11:01:55


VIEW MORE
story-1
Top 10 Fords at 2026 Carlisle Ford Nationals

Slideshow: Top 10 Fords at 2026 Ford Nationals

By Joe Kucinski | 2026-06-09 11:10:08


VIEW MORE
story-2
3 Best / 3 Worst Parts of Modern Ford Ownership

Based on years of owning multiple modern Ford products.

By Brett Foote | 2026-06-09 10:53:36


VIEW MORE
story-3
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

SPONSORED: From muddy boots to rain-soaked cargo, these upgrades address some of the most common frustrations Ford truck owners face every day.

By Pouria Savadkouei | 2026-06-08 18:50:34


VIEW MORE
story-4
Every 2026 Ford Engine Explained

Here's everything you need to know about every Ford engine available for the 2026 model year.

By Brett Foote | 2026-06-05 12:58:01


VIEW MORE
story-5
10 Ugly Ford Trucks That We Still Kinda Love

Slideshow: 10 ugly Ford trucks that we still kinda love.

By Joe Kucinski | 2026-06-03 09:51:16


VIEW MORE
story-6
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-03 15:43:58


VIEW MORE
story-7
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-06-03 11:38:36


VIEW MORE
story-8
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Slideshow: 10 most expensive Ford trucks ever sold on Bring a Trailer.

By Joe Kucinski | 2026-05-27 16:24:34


VIEW MORE
story-9
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Here's everything that has changed for the latest model year.

By Brett Foote | 2026-05-27 16:17:28


VIEW MORE