Help #2

[FordGuy100]

STOP!


Don't make changes until you know they are necessary!


Do some tests on the glow plug relay. Disconnect ALL small wires from the glow plug relay. Do the following....the ignition key should be OFF.

First test - Using a test light, verify you have battery voltage at the large lug NOT attached to the Z strip.

Second test - Verify that a test lamp will light when one side is connected to the large lug with battery voltage, and the other end is connected to the lug with the Z strip. Leave this light connected, and illuminated. (note... this light is being grounded through the glow plugs, so they all must be connected). If the light does not light, then your glow plugs are not connected or there is a break in the wire.

Third test - Connect one of the small terminals to a good ground, and then using a short piece of wire, connect the other free terminal to the large lug with battery voltage on it. You SHOULD hear the relay clunk, and the test light should go OUT. If this does not happen, then your relay is bad.

Sounds about right to me. Except I was going to say ground the test light out and attach it to the glow plug side large terminal, then using a ground on one small post, and a battery hot on the other, see if it lit up.

My thinking is that somewhere in your wiring you are not getting power, or a ground to one of the small terminals. If you do, and its not clicking, then relay is bad.

 

[alienturtle]

See, inside a relay there is an electromagnet, on a spring. You have two small terminals, one is a ground, one is a power. When both are applied as such, the electromagnet energizes, and then closes the circuit (electromagnet is attracted to some steel in the bottom, when you hear the click, thats the electromagnet hitting it, and closing the circuit), when that happens, current flows through the relay. When either the power, or the ground is interupted, the electromagnet de-energizes. And since it sits on a spring, it gets sprung up, and the circuit is open.

and thats how you make a tiny little button or switch ect. open or close a HUGE high amp circuit. little switch controls the big switch which controls the high amp item. Thank you Joseph Henry. greatest invention ever

 

[badasp118]

Well I will do the tests, But i do not have power to the glow plug stud at the z strip. I have power to the Power lug, but appear to have no change in voltage as my volt meter is not fluctuating when the glow plug relay should be activating, like it used to. I hear the click of the ip, but nothing else. I am almost convinced that it is a ground problem.

 

[badasp118]

one good thing though, all of the junk autolight glowplugs came out with no swelling, and no problems. I am thankful for that.........

 

[Cincinnati Guy]

I felt like I was hijacking your thread, but my problem is identical. I did the test mel said well actually only the first one. I installed a new solenoid which its a starter solenoid identical to a GP solenoid and I took all the small wires off and attached one end to one big terminal and the other end to the big terminal where the Z strip is and the test light lit up. I didnt do the other test cause its dark and cold out.

 

[badasp118]

No problem on the hijack as its all the same and it helps us learn. I used a borg Warner starter relay on mine. Napa guy is an old idi mechanic and he swore that the relay is the same and he has used em for years. I'm starting to think its is ground related or bad wires.

 

[Cincinnati Guy]

My napa told me there not the same, I do remember reading on here that there the same exact thing but the starter relay is just cheaper. The only thing I seen different was the bigger nuts were just a little bigger on the new solenoid.

Did you do the test Mel posted?

 

[Cincinnati Guy]

The original Solenoid I took off my truck was cracked down the side, so why not keep tearing into it to see whats inside.

Here so we know whats on the inside.

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[itsacrazyasian]

the difference between a starter solenoid and a glow plug solenoid is the little stud on the glowplug relay is the ground vs the body is the starter solenoid ground and the I terminal on the solenoid has 12V when triggered usually for a timing retard.

 

[icanfixall]

Well there you go... Its great to "see" the inside workings of a solenoid but. You have to remember something. You get what you pay for on electrical parts... Mel proved this out some time back at a ralley. He took apart two solenoids... One was an aftermarket and one was a Ford part... The aftermarket looked exactly the same on the outside but the insides were very differant. cheaper material... smaller contacts and just poor workings... these solenoids leave some material from the contacts to the round copper disc. When they start swapping metals they build up resistance. Then you need to hold the key on longer till they work... Sound like whats happening to some of you guys... turn on the ingition and hear nothing. then things start to work... thats heat building up and creating the contact in the solenoids... You are being told things are not working properly and time to replace parts... Its just understanding the messages your getting thats tuff.... glad you are running fine again... thanks for the great picture too... Nothing worse than a blurred picture when asking the board... Whats this.... I'm about to answer... A very bad picture....Sometimes

 

[Cincinnati Guy]

Ill try to get a better picture, I was just in a hurry and snapped it with my cell phone.

 

[Agnem]

I did an extensive review of what was basically the same problem on a truck that was at the 08' rally, owned by Gary (EMD_Driver). He had cronic problems with his 7.3 glow plugs, and we worked tirelessly to resolve them. Ultimately, although we had 3 glow plug relays on hand, all were found to be bad. All were also cheap aftermarket types that only lasted a few glows. These pictures tell the story.

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Notice the pitted and burned contacts on both the contactor and the studs. It only takes a few arcs on a relay of this type to build up enough carbon that they no longer conduct, or conduct sufficiently. The major difference between these cheap ones, and a genuine Motorcraft relay, is that these have a bar that contacts the same spot over and over again. The Motorcraft ones have a disc, that rotates some with each use. Consequently, your relay never closes on the same burned spot over and over again. This produces a much better, longer lasting relay. Yes, ANY relay will work. BUT.... for how long, is the differentiating factor. DON'T GO CHEAP ON THIS ITEM. Do the test I laid out to determine if you in fact need to spend money or not.

 

[huse]

Hi, i have a problem with my gp circuit.



I have tested the relay and it seems too work like it should.

I have new zd9 plugs, two new deka 665 mf batteries and new battery cables from custombatterycables.com
I also replaced the starter motor the previous winter.

Come to think of it i didn't notice the problem before i changed the batteries and cables. But then again the outside temperature dropped considerately, under 0 degrees F

My problem is that the glow plugs work some times and some times they dont. I can see on the voltmeter in the car when they draw current and when they dont. The WTS light works just as it should.

When it started the first time i turned the ignition key, they didn't glow but if i turned it off and on again it worked.

Lately it's taken alot more time for them to come on.
They work sporadic.

It can glow right away or it can take 15 minutes before i have any glow.

Any ideas anybody?

And i've been wondering about the workings of the glowplug controller, how does it work? what its function?

Thanx

Pardon any grammar and spelling faults. Im from Norway.
But i guess my english is better than your norweigan

 

[badasp118]

Well I'm still fighting mine, and I'm getting ready to go do the tests Mel suggested. Now as for the last entry, Huse you are very correct...my Norwegian language skills SUCK! Lol...I don't even know how to order a beer and that's very important. Lol...if anyone can help you these guys can.

I swear the combined knowledge on this board is a wealth of information. I have even told a lot of professional diesel mechanics about this board and they say that they even learn a lot here!

 

[badasp118]

I did the tests Mel suggested n they showed the relay was bad. So I tried three other relays including one off my buddies tuck. None worked however they all work in his f350. All the wiring seems fine...I'm at a loss.....