GLOW PLUG LIGHT

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Jul 8, 2010 | 09:41 PM

HAWGMAN341

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GLOW PLUG LIGHT

O.K. I'M NEW TO THIS DIESEL THING.... MY GRANDFATHER LEFT ME HIS 1986 F250. I KNOW GAS ENGINES BUT VERY LITTLE ABOUT DIESEL. FIRST OF ALL DOES THE INDICATOR LIGHT ON THE DASH ALWAYS HAVE TO COME ON BEFORE YOU ARE SUPPOSE TO HIT THE STARTER? IT CAME ON IN THE WINTER BUT NOW IT DOESN'T AND THE TRUCK IS HARD TO START IN THE MORNING. IT HAS A 6.9 LITER INTERNATIONAL MOTOR WITH ABOUT 90K(?) ON THE CLOCK. DO I NEED TO REPLACE THE RELAY FOR THE STARTER GLOW PLUG? DROP THIS DIESEL DUMMY A LINE IF YA HAS ANY IDEAS...... THANKS HAWG OUT.....

Jul 9, 2010 | 06:32 AM

megawatt00

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Joined: Jan 2008

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From: Rochdale MA

Welcome to FTE Hawgman. I moves your thread from the general diesel to the pre powerstroke forum, The guys is here are very knowledgeable and will be more than happy to help you out!

Jul 9, 2010 | 07:49 AM

fuzzy1626

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Joined: Feb 2007

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From: Taylorsville, NC

Welcome HAWGMAN341. An 86 would be the old style glow plug system (unless it's been changed) which I'am not that familiar with. Someone else will be along shortly.

Jul 9, 2010 | 08:25 AM

Lazy K

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https://www.ford-trucks.com/forums/9...old-style.html Have a read through this thread.
And yes the WTS light should come on before each start. First thing I would do is to use a test light to check each glowplug in turn and replace any that are bad, then see if the WTS light comes on.

Jul 9, 2010 | 12:46 PM

Festus Hagen

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From: Maine (NorCal Native)

***** The following assumes you have already checked cables, connections, cab, chassis and engine grounds. *****
***** That the water temp is below 112F degrees. (ie: cold motor) *****
***** When testing energize briefly, long enough to get the answer, no need to overheat things and no more than 10 seconds *****

Unplug the forward (towards front of truck) most connector on the Injection pump, this prevents overheating the FSS.

*** Glow Plug Test. ***
Test light test of the glow plugs:

Unplug the Glow Plugs.
Attach one end of a test light to 12v+ battery.
Touch the other end to the terminal on the end of the Glow Plug (where you unplugged the harness)
Does it light up?
- Yes, Chances are it's good.
- No, Replace with Motorcraft/Beru ZD1A for 83-86, ZD9 for 87-94.5.
This test is susceptible to miss diagnoses and should only be used for a quick reference.
To do a positive test use a volt/ohm meter and test the ohms between the terminal and base. Should be .5 to 1 ohm resistance.

Test that you get power to the glow plugs:

Unplug a glow plug.
Attach one end of a test light to the glow plug wire.
The other end to ground.
Momentarily turn the key on while watching the test light.
Does it light up?
- Yes, test Glow Plugs.
- No, test Controller, Relay.

*** Pre '87 Controller, Relay test. ***
The relay is attached to the right (passenger) inner fender and has 4 terminals.

1 large terminal (Input Terminal) goes to full time 12v+. (battery)
The other large terminal (Output Terminal) goes to the glow plugs.
1 small terminal (Power Terminal) is controlled 12v+ from the controller. (Purple wire)
The other small terminal (Ground Terminal) goes to ground. (white with black tracer (I think))

Ensure there is 12v+ to the Input Terminal of the relay.
Ensure Ground is good, both the base and Ground Terminal.

Relay test:
1. Attach one end of a test light to ground.
2. The other end to the Output Terminal of the relay.
3. Remove the small purple wire from the glow plug relay.
4. Momentarily apply 12v+ to the Power Terminal on the relay. (where purple wire was)
  Does it light up?
  - Yes, relay MAY BE good.
    - Test voltage at the battery and the Output Terminal on the relay while relay is energized. BE QUICK. (10 seconds or less)
    - Voltages should be close to the same. If not replace relay.
  - No, Relay is not working.
Controller test:
1. Attach one end of a test light to the relay Power Terminal (purple wire, do not remove from relay)
2. The other end to ground.
3. Turn the key on while watching the test light.
  Leave the key on until the test light goes off (or cycles) or 10 seconds which ever occurs first.
  Does it light up?
  - Yes, The controller MAY BE good.
    - Does it go off by itself? (It may cycle, thats good)
      - Yes, Controller is good.
      - No, The controller has FAILED ON ... Replace!
  - No, The controller is bad replace.

-Enjoy
fh : )_~

Jul 10, 2010 | 05:00 PM

HAWGMAN341

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GREAT THANKS

WOW. THANKS ALOT FOR THE INFO... I'M GOING TO TRY WHAT YA SENT ME AND SEE WHAT HAPPENS.... I HOPE IT'S NOTHIN' SERIOUS, MY GRANDDAD USED TO TAKE GOOD CARE OF HIS VEHICLES, I GUESS HE GOT SOME ONE ELSE TO DO IT FOR HIM AND THEY DIDN'T DO WHAT THEY WERE SUPPOSED TO. THANK YOU AGAIN. HAWG OUT...

Jul 10, 2010 | 06:27 PM

FORDF250HDXLT

Fleet Owner

Joined: Jul 2006

Posts: 20,322

Likes: 789

From: Mi'kma'ki

compared to PS diesels,there's really nothing to serious that can happen to an IDI.even when a replacement engine is in need.1 single injector on today's diesels cost more than a good used IDI engine does.
your grandfather left you a nice truck.good luck bringing her back up to par

dang,Festus,your posts keep getting better and better as you cover more/add to them.nice job!

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Jul 15, 2010 | 10:09 PM

HAWGMAN341

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Joined: Jul 2010

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O, O.K. I usually just type. I didn't mean to seam rude. Uh, by the way "lose" not "loose" spelwing iz inpoten yu no. Just messin' with ya. I've every intention of restoring my grandpa's old truck. I have a 1985 Dodge p/u i've had since new, now it's being replaced with a newer 1986 ford f250. I'm going to visit our local classic car/truck lot (salvage yard) for a tail gate and parts, mine doesn't have one. Well I'm gotta go right now. Thanks again for the advise and all.... hawg gone....

Jul 15, 2010 | 10:16 PM

#10

kenpobuck

Cargo Master

Joined: Mar 2006

Posts: 2,789

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From: Sand GAp, KY

You don't want to read any of Joe's posts then lol.

Jul 15, 2010 | 10:38 PM

#11

Festus Hagen

Methanoholic

Joined: Mar 2009

Posts: 6,442

Likes: 8

From: Maine (NorCal Native)

Ouch!! Hey, not once have I ever stated I could spell ... Neither did any of my teachers!

Uh, by the way "Seem" not "Seam"

Wish i could get my hands on my grandpa's truck!
To many years ago it disappeared.

-Enjoy
fh : )_~

Jul 15, 2010 | 10:42 PM

#12

Rick Wallace

Posting Guru

Joined: Dec 2009

Posts: 1,272

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Quote:

Originally Posted by kenpobuck

You don't want to read any of Joe's posts then lol.

Hell,you have to be a vetran FTE reader to read Joes post anyway!!!!!!!!

I been on 8 months and still cant figgure out most of them!!!!!!!!!!

Jun 22, 2021 | 11:57 AM

#13

nicklord253

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Joined: Jun 2021

Posts: 1

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I’ve ran through all these tests and everything is coming out good. Glow plug light for myself isn’t turning on. Tried to trace back the wires but that lead into nightmares of harnesses from prior owners. Any idea for a quick fix?