Glow Plug Controller Broke Off!

dgr · Jan 3, 2020

BeastMaster said:
I am a bit puzzled. I have a 94 E350 van, 7.3 L N/A, glow plug controller at the rear of the engine, easily accessible via removal of the dog house in the cab.

I flat do not trust that relay.

That is only the controller. The relay that is triggered by it is elsewhere. You will need to manually trigger your contactor if you don't trust the controller. The relays aren't known for sticking on.

Leave the controller. Replace the relay if you want. Run a manual push button to the relay.

BeastMaster · Jan 3, 2020

Thanks! I think my 1994 7.3 is made a little different. To the best of my knowledge, my controller does not sense engine temperature. It seems to have one small wire for 12V key on, one small wire for WTS light, one big wire straight to battery, and the other big wire branching out to the eight glow plugs.

Cubey · Jan 3, 2020

dgr said:
That is only the controller. The relay that is triggered by it is elsewhere. You will need to manually trigger your contactor if you don't trust the controller. The relays aren't known for sticking on.

Leave the controller. Replace the relay if you want. Run a manual push button to the relay.

Um, no?

The 84-86 have the relay elsewhere. (By the left side headlight on my van, trucks might the same?)

87 6.9 and 88+ 7.3's have the relay attached to the top of the controller, located behind the CDR on the NA engines.

Cubey · Jan 3, 2020

BeastMaster said:
Thanks! I think my 1994 7.3 is made a little different. To the best of my knowledge, my controller does not sense engine temperature. It seems to have one small wire for 12V key on, one small wire for WTS light, one big wire straight to battery, and the other big wire branching out to the right glow plugs.

This is the 84-86 6.9 controller (rear of block) and relay (above left headlight):

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This the 1987 6.9 & 1988+ 7.3 (IDI) controller and relay in one, located behind the CDR on the NA engines. (Dunno where on factory turbo). The brown, round thing on top is the relay, the black box on the bottom is the controller.

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BeastMaster · Jan 3, 2020

Yup, that last photo is the one I have.

I just do not trust that new " exact replacement " contactor.

Glad to hear they do not have a history of welding their contacts together.

Having contactor contacts weld "closed" was nightmare stuff for me when I used to work in a petrochemical plant.

Cubey · Jan 3, 2020

BeastMaster said:
Yup, that last photo is the one I have.

I just do not trust that new " exact replacement " contactor.

Glad to hear they do not have a history of welding their contacts together.

Having contactor contacts weld "closed" was nightmare stuff for me when I used to work in a petrochemical plant.

My 87's relay failed just from getting weak/sticky, so it wouldn't always activate. I bought a new from O'Reilly and swapped it out. Fixed the problem fine. Just unbolted it from the controller and installed the new. Fixed the problem.

compressionignitionrules · Jan 3, 2020

anybody ever use a torx bit socket in place of an extractor? the piece is aluminum and an extractor should bite into it.......................

Stu Bailey · Jan 4, 2020

So I’ve installed the manual glow plug switch and the glow plugs aren’t getting power... The engine is cranking and exhaust is coming out. I attached a picture of the relay, maybe that is bad now? So the yellow circle is the positive connection from the battery where I have 12VDC. The red circle is, was, where the purple wire connected to the relay post. I clipped it and used it to hold down the new ring terminal that goes back to my momentary push button. That terminal has 0VDC for some reason... even when I turn the keys to on. Shouldn’t it have 12VDC as well? Also, a 10amp fuse should be sufficient for the push button right?

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Cubey · Jan 4, 2020

Stu Bailey said:
So I’ve installed the manual glow plug switch and the glow plugs aren’t getting power... The engine is cranking and exhaust is coming out. I attached a picture of the relay, maybe that is bad now? So the yellow circle is the positive connection from the battery where I have 12VDC. The red circle is, was, where the purple wire connected to the relay post. I clipped it and used it to hold down the new ring terminal that goes back to my momentary push button. That terminal has 0VDC for some reason... even when I turn the keys to on. Shouldn’t it have 12VDC as well? Also, a 10amp fuse should be sufficient for the push button right?

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That's the starter relay by the voltage regulator. The glow plug one is on the driver's side above the headlight. Assuming it's like my 85 E350 anyway. (edit: oh it's on a truck. getting confused.. lol)

Starter relay:

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Glow plug relay:

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Stu Bailey · Jan 4, 2020

So I had it right? I hope so! If it was the started relay then the engine wouldn’t crank right? Either way, aren’t these relays internally connect so shouldn’t I be seeing 12VDC?

Cubey · Jan 4, 2020

Stu Bailey said:
So I had it right? I hope so! If it was the started relay then the engine wouldn’t crank right? Either way, aren’t these relays internally connect so shouldn’t I be seeing 12VDC?

I guess so. Here's a video about it...

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Stu Bailey · Jan 4, 2020

Been watching that one, that’s how I learned to do it haha alright, we’ll thanks Cubey, you the man. Really appreciate all the advice so far! Awesome rig by the way

Cubey · Jan 4, 2020

Stu Bailey said:
Been watching that one, that’s how I learned to do it haha alright, we’ll thanks Cubey, you the man. Really appreciate all the advice so far! Awesome rig by the way

Did you give it positive 12V or ground through your push button? On 6.9 controller style setups, the button needs positive. On the 7.3 style (including 87 6.9s) they need ground.

Selahdoor · Jan 4, 2020

The small terminal that you refer to as "0-volts"... Remove the purple wire, and put a nut on, to hold your white wire on. You don't want that purple wire reconnected.

Your white wire should go to a momentary on switch. The other side of your momentary on switch should go to a 12 volt supply.

You are not switching ground, you are switching power.

The other small terminal should be a ground.

So...

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Just pull that wire off, where I say to check for voltage.

You should have zero voltage from the wire.

It should be a ground wire.

If you have voltage there, then this is wired backwards. And you will then make your switch a ground switch.

But if it is wired correctly, with the purple wire pulled off, the OTHER wire should be a ground, and your white wire should supply power.

dgr · Jan 4, 2020

@Selahdoor has it right. You can test the relay by touching a hot wire to the post where the purple wire was. It should click and your wts light should go on.

Does your momentary switch supply power or ground?

If it supplies power, it goes to the purple side.

If it supplies ground, disconnect the wire on the small post opposite the purple wire post. Put a jumper from the battery side of the relay to the purple post. Put the momentary switch to the other small post.

Glow Plug Controller Broke Off!

dgr

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BeastMaster

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Cubey

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Cubey

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BeastMaster

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Cubey

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compressionignitionrules

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Stu Bailey

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Cubey

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