I also depends on how cold outside it is to how long it stays on. When it was really cold my wts wouldn't even come on, entirely new glow plug system but I would wait until the voltage gauge and relay started clicking that's how you known its temperature cycling. Even when hot though I'd start my truck and glow plugs would keep voltage low for about 15 seconds while running.

 

Well this has to be a fluke. I plugged it in last night because it was supposed to hit freezing, it started better than it does warm! I'll keep an eye on it. If it keeps staring this good plugged in I'll know for sure it's the glow plugs. I was thinking it might be something else but wow.

 

OK so I had put in a 4ga power lead and it had still been starting hard but it was still starting. The starter was VERY slow, and I replaced that last night. Today at work it wouldn't start without ether. Apparently the guy who changed them put in autolite plugs. It's turning over nice and fast but I don't think the plugs are even working anymore.

I'm planning on getting a 6.0 glow plug harness (mine is shot) and new motocraft plugs. I unhooked the power lead to the relay (so I don't destroy the engine using ether). Should my WTS light illuminate for about 3 seconds with the glow plug power unhooked?

 

Since you didn't get an explosion using the ether, you are correct, your GPs are most likely inop. Plug it in tonight, put it on a timer to get 2-3 hrs run time before leaving. And yes, get those Autolites out of there (knock wood, they'll not be swollen and will come out).

WTS light is controlled by the controller, not the relay, so yeah, WTS normal ops would be expected even with an inop or disconnected (contact circuit) relay.

 

Yeah I plugged it in. I don't have a timer yet so I'm just leaving it plugged in overnight.

I left the key on for a couple minutes before shooting the ether to avoid any possible explosions.

I was mainly curious if the light being on was a sign of a bad controller but sounds like I might be OK in that regard.

Thanks!

 

Well yesterday after I got it running I drove it 50min away from home and it started right up again after 5min. When I got back home I ran into Walmart for about 15min and she started up fine. Plugged her in overnight and she fired right off like nobody's business, it's about 40 degrees or so this morning.

So I'm thinking definitely no doubt about it something to do with the glow plugs right? Is there anything else that could cause these symptoms? If not I'm going to replace the harness and plugs. If they still aren't working right I'll bypass the controller until I can afford a new one.

 

all the controller does it cycle the plugs ..

3 seconds on 5 seconds off X4

you can do that with a momentary switch , and delete the controller ..

otherwise it's a matter of when, not if , it will stick on and fry the plugs again .

 

plus with the stock controller, every time you start the truck ..

it will cycle the plugs .. even when it's warm and not required ..

straining the batteries and plugs for no reason ..

you only need the plugs when it's cold ..

if it's not super cold only cycle it 2-3 times ..

if it's dead freezing .. cycle it 5-6 times then start ..

 

I thought I had read the newer 7.3 controller (87?-94) was pretty reliable?

 

it is. once the engine hits around 120 degrees the controller shuts off, and will not start cycling the glow plugs again until the engine drops under 120 degrees.
and the power going to the glow plugs is also dependent on the temperature of the engine. if it is 90 degrees, it may only cycle for 5 seconds. but if the engine is 10 below it may power the plugs for 45 seconds.
my 88 with over 494,000 miles on the clock is on the third glow plug relay, but still has the original controller.

 

I thought I'd write a new post on here but I can't seem to find how to start a new Post... Fairly new on this site and still trying to work my way around with limited time.


Glow Plugs? Prior , I Replaced all my Autolites with Motorcraft/Beru and found one of the electrical contacts on rear plug was broke in half which I soldered together. Another Plug was swelled yet came out. My starting issues were resolved. Now, I just tackled my last project on the truck for the season. I purchased a new Dipaco Return line Kit which included IP O rings for doing a more complete job. I noticed a small fuel leak at the very end of my return pipe where the brass nuts thread together. I was also smoking a little more than what seemed norm and seemingly poor fuel mileage. I removed all fuel lines from injectors and went to remove the three bolts holding the IP in place. That left lower nut was missing. The lower right was loose. The top was all that held IP secure. Thus, the reason I am my own Mechanic! Unbolted the IP from under the cover and removed the IP with fuel lines still connected. I took apart the head of the IP to check filter. Yup a few particles against the filter; but overall very clean. Always a good idea the check that filter before deciding an IP is bad. O ring sealing IP to timing gear was hard and brittle. Glad I went with the extended fuel kit! That kit also had the rubber for the ends of the pipe fuel lines where they connect onto the fuel filter and each end of the return pipe. Next I removed all my fuel injectors and discovered three of them to be leaking fuel as the needle valve wasn't seating or closing. I placed each one in a separate container to soak in Naptha over night. They are easily broken down by placing them in a vice with the needle end up and fitting the correct wrench over the star end... it takes a little muscle to open them. Careful to open each over their own container as to ensure the number of washers stay with each injector. The needle ends were glazed over and krudded with dried burnt fuel.,, turned to varnish. Again they soaked in Cleaner. I lightly steal wool all krudded areas. Make Sure they are dried with air pressure in all ports needle ..etc. As they have to be assembles very clean; lint free as exactly they came out. I did not have a facility near me that I know of to test for pressure. But since they each were kept separate and assembled exactly as they came out.. Can't be any worse than they were. ( I have heard of people buying New injectors and tossing the old away... They are rebuildable and the number and thickness of the washers adjust the pressure inside each injector. As new, the number of washers in each injectors is determined by the slight difference in the spring resistance and adjusted accordingly.) All reassembled with new fuel return lines and caps... Good to go! I disconnected my glow plug harness at the main connect. I turned my engine over ...on ...off for some time. I reconnected my Harness and turned engine over. No Start? Checked engine Compartment and smelled plastic. Discovered Main harness connect melted where Yellow glow plug leads enter connect. Bypassed and wired them together. With effort finally got it started. After a few it cleaned up and ran with good strong tick. Smoke cleared off completely. Diving, it was no longer seeming sluggish but had an added pep/power that I've never felt before. Went out this morning to start it. First slowly unscrewed fuel filter and tightened back up as fuel started to seep out. Great No Air entry! Turned on Key and noticed glow plug light did not stay on as long as it had been ... 6 seconds vs the normal 10. I had to crank for several moments before it finally started. When it started it let out a big puff of Grey Smoke but than cleared off quick and all seemed right.


(I do have a little smoke when I removed my oil fill cap... When I seal hand over opening I feel no pressure.... if I rev it up it even feels as if it sucks slightly inward... Is this Normal?? ... I don't have a Valve issue? )


Why did the contact suddenly melt and what other damage can that cause? I guess, I'll have to check glow plugs? Can it be that not enough fuel had entered ( since the IP was drained) and without fuel the Glow plugs burned. I didn't realize they were so sensitive??

 

Thanks for chiming in Fellow Members! I went out to check my Glow plugs with static light. They all checked fine. Glad I didn't need to purchase more glow plugs. In the process I discovered two bullet leads going to GP were snapped in half. That must have caused the melt down in the electrical connect. I've done a search for new bullets to replace the old rather than try and solder the pieces together. I've read where others have purchased #14 electrical bullet connects and are not very satisfied with the tightness of the fit to top of GP. FYI, I came across someone who used the wiring harness for a Ford 6.0L. The fit is great and very simply adjusted to fit as if OEM. I found a new harness on Ebay selling for only $20.

 

This is the plan for me as well except I will be replacing the glow plugs with Motocraft ones at the same time. I won't be able to do mine until spring but if you install the 6.0 harness just let me know how it goes.

I'd gladly show you how to make a thread but my computer is down and using it from my phone is very different sorry.

 

I have used the 6.0L harness, worked fine for 10K until the truck was totaled.

https://www.ford-trucks.com/forums/1...-for-50-a.html

 

Hi Shawn! You, are where I came across the info on the 6.0 harness. I just ordered off ebay both sides for 19.95 . It seems it will be a great replacement. I notice that all my old oem bullet connects do not fit too tight to top of GPs. I tried to crimp each closed tighter but its limited as to how far they will tighten. I'm thinking that the original GPs on these engines had slightly larger glow plug stems/bullets. So that now they will not fit so tightly together. The new 6.0 harness probably fits more snug to the GPs as they both share the same gp size stems?


Are you that same member who lost his truck when it was parked on side of road and some drunk hit into a couple of vehicles... You were in court last I heard trying to get a settlement? You've not found a replacement yet?