Glow Plug Relay ?
Thread Starter
|
Freshman User
Joined: Jan 2009
Posts: 45
Likes: 1
From: Sheridan, Colorado
Glow Plug Relay ?
My 2003 7.3 Stroker has been having trouble starting first thing in the morning, or if it has been sitting for awhile in cooler temps. If I plug in the block heater then the truck fires right up. The only reason that I think there is a problem is because I have been able to start up with no issues in much colder conditions. Could the glow plug relay be going out? The other question I have is can anyone tell me where the relay is on a 7.3? I know that it is the part on top of the motor that looks like a starter solenoid, but there are two parts that look like that in that location. Which is which? Any help with this would be greatly appreciated.
Thanks, Ryno
Thanks, Ryno
Last edited by rynomush1; Apr 20, 2009 at 12:04 PM.
Hotshot
Joined: Jul 2003
Posts: 12,177
Likes: 40
From: Newport, WA
It is the brown solenoid closest to the firewall. As a test, when your motor is cold turn the key to on, open the hood, and put a large screwdriver, ratchet, or something else metal (or rig up a jump wire) across the 2 large posts on the GPR and leave it for 45 seconds to a minute. Then try to start the truck and see if it starts any easier. Another simple test is to put a volt meter on each of the large posts on the GPR. The post closest to the fender should have +12v or so all the time, the other one should have +12v only when the relay is on during a cold start. If there is a significant voltage drop to that post of the GPR (more than 1v or so) the relay is done. It could also be your glow plugs, and you can ohm them out to see if they are still good or not. Start with testing the GPR and go from there.
Thread Starter
|
Freshman User
Joined: Jan 2009
Posts: 45
Likes: 1
From: Sheridan, Colorado
It is the brown solenoid closest to the firewall. As a test, when your motor is cold turn the key to on, open the hood, and put a large screwdriver, ratchet, or something else metal (or rig up a jump wire) across the 2 large posts on the GPR and leave it for 45 seconds to a minute. Then try to start the truck and see if it starts any easier. Another simple test is to put a volt meter on each of the large posts on the GPR. The post closest to the fender should have +12v or so all the time, the other one should have +12v only when the relay is on during a cold start. If there is a significant voltage drop to that post of the GPR (more than 1v or so) the relay is done. It could also be your glow plugs, and you can ohm them out to see if they are still good or not. Start with testing the GPR and go from there.
Thanks, Ryno
Posting Guru
Joined: Dec 2005
Posts: 1,334
Likes: 0
From: Parker, CO
The Glow plugs heat up the engine when its cold so it starts. If the engine is cold it wont start or it will smoke a lot as there is unburned fuel. I would try jumping the two large posts on the GPR, if it starts like it should, you know you have a bad GPR.
Here is a write up and if you do indeed need a new one, get a Stancor, you will never have to replace it again!
Welcome to guzzle's Stancor GPR replacement Mod Web Page
Here is a write up and if you do indeed need a new one, get a Stancor, you will never have to replace it again!
Welcome to guzzle's Stancor GPR replacement Mod Web Page
Hotshot
Joined: Jul 2003
Posts: 12,177
Likes: 40
From: Newport, WA
GP's have no effect on performance, they are just there to aid in cold start situations. The only thing you might notice with bad GP's is a lot of white smoke until the motor starts to warm up.
Thread Starter
|
Freshman User
Joined: Jan 2009
Posts: 45
Likes: 1
From: Sheridan, Colorado
The Glow plugs heat up the engine when its cold so it starts. If the engine is cold it wont start or it will smoke a lot as there is unburned fuel. I would try jumping the two large posts on the GPR, if it starts like it should, you know you have a bad GPR.
Here is a write up and if you do indeed need a new one, get a Stancor, you will never have to replace it again!
Welcome to guzzle's Stancor GPR replacement Mod Web Page
Here is a write up and if you do indeed need a new one, get a Stancor, you will never have to replace it again!
Welcome to guzzle's Stancor GPR replacement Mod Web Page
One more question about the GP, would I notice a problem starting all the time or just when it is cold?Thanks again, Ryno
Trending Topics
Hotshot
Joined: Jan 2008
Posts: 13,144
Likes: 11
From: Rochdale MA
Just when the engine is cold. The colder it is the longer the glow plugs stay on. Some of us have tied a 12V led into the GPR to see how long they stay on.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Freshman User
Joined: May 2007
Posts: 47
Likes: 0
Join the club. My glow plug relay went bad, and when I replaced it, it still wouldn't work. I put the LED in the circuit to see if the glow plugs were being energized, and nothing. I finally ran a wire from the ground side of the relay to the inside, put a small push button in the dash, and ran the other side to a ground. Now, I just hold the button down, watch the LED come on, and wait 30-45 seconds, and she fires right up.
Thread Starter
|
Freshman User
Joined: Jan 2009
Posts: 45
Likes: 1
From: Sheridan, Colorado
Right-on everybody, this is why I love and recommend this site to everyone that I know! I asked a question this morning, and by this afternoon I have the advise I need!
Thank you all for your help, Ryno
Thank you all for your help, Ryno
