7.3 IDI glow plug harness

[papadiesel]

I have seen several people making a plug harnesses for early 7.3 nonturbo I have seen yet some use the 6.0 connectors, I have used the after market bullet style connectors and they never quite stay on does anybody make a harness in which the connector stay on better

 

[IDIBRONCO]

Ask Thewespaul what he uses on his. I'm not sure if the connectors are from the 6.0 or not.

 

[papadiesel]

thanks i will

 

[Cubey]

It's curious that people don't put blade connectors and use the 6.9 style plugs. Or are the threads different between the blade and bullet GPs?

 

[papadiesel]

different controllers, more resistance with blade style, would not go backward to earlier more problem prone glowplug

 

[dgr]

That's the first I've heard the blade style glow plugs are more problematic. What exactly makes them inferior?

 

[papadiesel]

just an older design, more resistance at the blade, worked on both idi idit for over 30 years and had more issues with the 6.9 system

 

[Cubey]

just an older design, more resistance at the blade, worked on both idi idit for over 30 years and had more issues with the 6.9 system

Interesting. What issues did they have, besides the controller? My RV could very well have the original glow plugs still and it's still starting pretty well when it's cold. I'm sure one or more are weak since it chokes a little and blows grey smoke, but compared to how bad my F250 got with 4 bad Autolites (last owner put 'em) it's doing pretty good.

 

[Philip1]

If you want to make your own glowplug harness and are having issues with the bullet connectors staying on, I found using either 3.5mm (for a tighter fit) or 4.0mm (easier install) silicone vacuum hose works well as a band on the connector. I used it on my truck and it worked well

Sent from my SM-G975U using Tapatalk

 

[snicklas]

I believe the issues with the 6.9 System was with the "dumb" controller, not the plugs. The 6.9 controller is basically just an on/off controller that runs the plugs. It's supposed to sense coolant temp also, and not run above a certain temp. They have a habit of failing and staying or, or will just run the plugs randomly. I've read may questions of why does my WTS light come on while I'm driving down the road.

The 7.3 System has an "intelligent" controller that monitors current draw, and runs the plugs accordingly. They normally fail off, and won't damage the plugs. This is also why there is the short cycle when there is a bad or unplugged glow plug......

I don't see an issue with the ZD-1 Blade Style Plugs, it was the controller used at the same time that had the issues.....

 

[Cubey]

I believe the issues with the 6.9 System was with the "dumb" controller, not the plugs. The 6.9 controller is basically just an on/off controller that runs the plugs. It's supposed to sense coolant temp also, and not run above a certain temp. They have a habit of failing and staying or, or will just run the plugs randomly. I've read may questions of why does my WTS light come on while I'm driving down the road.

I'm not sure about that. On restart, the plugs sometimes come on but don't stay on as long.

I haven't ever noticed WTS come on when driving, but Ford put it where you cant even see it (or the "ENGINE" light!) when driving, because the steering wheel completely blocks it from view during normal sitting posture. It does come on a few times when first idling until the cylinders/glow plugs get to a certain temp. And as loud as this thing is, it might be hard to hear. Putting in a 12v buzzer tied to the WTS light might not be a bad idea if running the controller like I am.

I think my 87 6.9 with the 7.3 system did the same though as I recall. Maybe I'm wrong on that though. It's been about 10 months since I drove it and I never paid much attention to that after a couple years of driving it, as long as it clicked on pre-starting.

Supposedly, the new controllers made today are solid state and fix the problem of old electro-magnetic ones.

Mine definitely has the old style, you can tell just by looking. It has a ********* cylindrical piece that sticks outward from the pigtail, plugged into the middle of it:

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The new ones don't have that area:

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DieselRX has one for under $70 and all 7 reviews are 5/5:
https://www.amazon.com/DieselRx-DRX01003-Glow-Plug-Controller/dp/B00TOZ9CUG

 

[dgr]

I'd be interested in how often these controllers fail on. I read a lot of "they're known for failing....". I don't recall reading, "MY controller failed in the on position...."

Probably should be a new thread but I'm lazy.

 

[papadiesel]

They changed systems for a reason, not just a "Ford" reason. The resistance on the connector is much higher and can become brittle and not as consistent passing current through as the newer design. Look at the zd9, 11 13 etc and they have kept the design of the connector end. We want the older design because it is hard to find replacement connectors that stay snug. Not dissing the older glow plug, just is not as consistent or as trust worthy. Worth changing out? If your keeping your 6.9, my 2 cents, yes. If your doing repair, probably not as you would have to change controller and glow plugs to be consistent. Any unnecessary resistance in any electrical system creates heat and brittleness shortens life and productivity. Motorcraft, Beru is still the only one I care to put in. Any other is an unnecessary gamble. So, unnecessary resistance at the spade connection is part of the reason of the design change. Take a look and compare the two.

 

[Cubey]

I'd be interested in how often these controllers fail on. I read a lot of "they're known for failing....". I don't recall reading, "MY controller failed in the on position...."

Probably should be a new thread but I'm lazy.

I think the problem lies in how the old ones have moving parts inside that can get stuck in the on position. Much like how relays and solenoids usually can get stuck in the off position, not activating unless you hit them with something. The new ones are solid state and have electronics that control it instead of mechanically.

My 87 F250's 6.9's 7.3 GP relay wore out and was sticking and not activating unless I took off the air cleaner housing and hit it with a plastic handle of a screwdriver a few times. Then it would click on like it should.

That's why you can sometimes hit starters to get them going if they have a solenoid/relay built onto them.

 

[lakesurfer]

I tried the "6.0 harness" thing. It "can" sortbof fit, but some of the connectors will have sideways torque on them because the spacing is not exactly the same. This was not acceptable to me so I went to a ton of trouble reworking it so it fit. Then, the connectors would not stay on well. I tore it all out and used the electrical connector method.