another glow plug question
Thread Starter
|
Senior User
Joined: Mar 2004
Posts: 281
Likes: 0
From: Buena Vista VA
another glow plug question
A buddy of mine just bought a 1990 F350 and the glow plugs are not working the relay has been replaced and still nothing what i was wondering is if there is something else that controls the relay im not sure were to start i have not had any problems like this on my 01 psd yet thanks for any help or suggestions
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 15
From: Nutter Fort, WV
Burnt out glow plugs will keep the new style glow plug controller from working.
One burnt plug changes the cycle time to a shorter duration.
Two burnt plugs usually will disable the glow plugs.
The new style system uses resistance feed back to time the heat cycle.
When a glow plug burns out, it changes the resistance the controller sees.
See this thread, there are two ways to check the glow plugs.
https://www.ford-trucks.com/forums/6...low-plugs.html
One burnt plug changes the cycle time to a shorter duration.
Two burnt plugs usually will disable the glow plugs.
The new style system uses resistance feed back to time the heat cycle.
When a glow plug burns out, it changes the resistance the controller sees.
See this thread, there are two ways to check the glow plugs.
https://www.ford-trucks.com/forums/6...low-plugs.html
Thread Starter
|
Senior User
Joined: Mar 2004
Posts: 281
Likes: 0
From: Buena Vista VA
thanks for the post next question is is this what contols how long the glow plugs stay on or is there something else that does that
Trending Topics
Senior User
Joined: Sep 2007
Posts: 129
Likes: 0
From: Baton rouge, Louisiana
when i start my 92 f350 diesel in the morning after the wait to start light goes off it still takes a long time to start. it starts fine the rest of the day after that, any suggestions?
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
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
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Senior User
Joined: Jul 2007
Posts: 190
Likes: 0
From: Chesapeake, VA
My 89 F350 is the same way. thats what im trying to figure out. What i do is i turn the key and wait for the wait to start light to go out and then i shut it off and i do that 3 time before starting. When i do that It starts right up.
Senior User
Joined: Feb 2007
Posts: 191
Likes: 0
From: Denair, CA
I was having problems with my controller basically giving me about a half second of glow before shutting off the GP's so I referred to the picture that Dave S. posted there and hooked it up to a manual switch inside the cab. Boy what a difference. Instead of killing my starter for 3+ minutes every morning I can now just hold the switch for around 10 seconds and she fires up like I was driving around all day. A modification worth it's weight in gold, especially since diesel starters aren't the cheapest. Might be a route you look into.
BTW, thanks Dave for that pic of the controller. It really made the job a breeze.
BTW, thanks Dave for that pic of the controller. It really made the job a breeze.
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 15
From: Nutter Fort, WV
Check your glow plugs.
If you have the new style glow plug relay in that picture, 87 thru 94 trucks used it, th eglow plug heat time is controlled by resistance feedback from the glow plugs to the controller.
One burnt out glow plug will make it cycle for a shorter amount of time.
Two burnt out plugs will make it even shorter.
And with three burnt out plugs, it probably will not cycle at all.
You should be seeing the wait to start light on for 10 or more seconds depending on the night time temps in your area.
If you have the new style glow plug relay in that picture, 87 thru 94 trucks used it, th eglow plug heat time is controlled by resistance feedback from the glow plugs to the controller.
One burnt out glow plug will make it cycle for a shorter amount of time.
Two burnt out plugs will make it even shorter.
And with three burnt out plugs, it probably will not cycle at all.
You should be seeing the wait to start light on for 10 or more seconds depending on the night time temps in your area.
Senior User
Joined: Jul 2007
Posts: 190
Likes: 0
From: Chesapeake, VA
Mine stays on for about 10-15 seconds. It has been in the high 40's low 50's at night here. Yesterday i didnt even cycle it, i just waited for the light to go out and it started right up. I had a problem with it running last week and i found a leaking injector. I replaced it and it has been starting fine since. I think i may have had air in the line or something.
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 15
From: Nutter Fort, WV
If the system you are asking about is on an 87 or later truck, you attach a wire to the white wire terminal on the relay after removing the white wire..
Run the wire inside the cab to a momentary switch.
The other terminal of the momentary switch goes to a good ground.
The ignition terminal is powered by the key switch.
The white wire goes to ground through the controller to complete the circuit and close the relay.
Run the wire inside the cab to a momentary switch.
The other terminal of the momentary switch goes to a good ground.
The ignition terminal is powered by the key switch.
The white wire goes to ground through the controller to complete the circuit and close the relay.