Newby working thru Glow Plug diagnostics

[Whitfield]

Step 1.
Unplug glow plugs and probe plug with test light hooked to +.
Bad glow plugs #2 and #7. Now I need to searh for a GP socket. Any tricks to getting out #7 ~ Can I get @ it thru thee fender well?

Step 2.
Jump blue wire on GP relay to ground and check for voltage @ gp wires.
All CHeck Ok

 

[Whitfield]

Next to work thru the GP module trouble shooting chart.

CUCV Glow Plug System Troubleshooting - CUCV Electric


I printed off teh chart last night and worked thru it this morning. Now I see I there were some instructions I forgot to print...

First, disconnect pink wire from fuel injector pump. Then, remove the printed circuit board from glow plug module. Check each circuit to the glow plug module as described. Trace any circuit that does not operate


Let me try again... Results in 10 min.

 

[Skinny]

You don't need a special tool, just a deep well socket.

If they do not come out, chances are they are swollen. Pretty good chance too! I had good luck running the engine till it gets very hot then loosen one stuck plug. Spray penetrating oil on it and twist with a vice grip. You may have to repeat several times but I was able to remove all of my swollen plugs this way without breaking one or with a special tool.

 

[Whitfield]

I think my 22v @ orange wire to GP is very bad / how much damage will this cause? Should I replace all ( 8 ) gp or just my bad ( 2 )?



Glow Plug Controler Harnes Diagnostics:


Wire color Key Position Norm / results

Purple white Start 12v / 8.24v

Light blue Run GP Relay energize / Yes

Dark Blue Run Jump wire to ground for wait light / NO

Pink Black Run aprox 12v @ wire / 11.63

Orange Run Jump lt blue to grnd. 12v / 22V

Yellow Off 800 ohms min at wire 900 / 1K

Black Off 0 Ohms at wire 0 / 1.3 - 2.2

GP Relay Pink Black (TO) lt. Blue
Off 6-10 ohms 6-10 ohms / 14.4 - 18.6

*** Note Ohm testing is only as good as your tools / meter / jumper / ground.

 

[Warthog]

Have you read this thread on how the GP system works?

http://www.steelsoldiers.com/cucv/62477-gp-module-theory-operation.html

 

[Warthog]

The orange wire senses the voltage being sent to the glowplugs.

First check to see where the small orange wire connected at the GP relay on the firewall. The original wiring diagrams show it connected to the wrong place. It should be connected to the same side as the large orange wires.

If everything is working correctly and ALL the glowplugs are good, then the voltage at the orannge wires will startout at 24v and then drop to ~12v when the Resistor pack and the GPs heatup.

 

[Whitfield]

Thanks~ I am still strugelin to wrap my head aroudn it all together. I've read so much in the last 5 days.

My original test was with all GP unpluged, I need to do a recheck but feel as though I should replace my 2 dead GP's first.


Somewhere 2-3 days ago I read a great piece on glow plugs and what brand the 6.2 prefers. Searching ~ but burried with information.

 

[kingchr]

I have had very good luck with AC Delco 60Gs as have many on this site. They are self limiting, so they SHOULDN'T swell on you like the old ones... I'd replace 'em all with these.

Just my 2Cents...

Have a good one, good luck,
Christopher

 

[Whitfield]

( 8 ) 60g's on the way.

 

[cpf240]

Sounds like you are on a good path to getting your GP system up to snuff.

For mine, I pulled the rear battery and tray to gain easy access to the right rear glow plugs. This also allowed me to repaint the battery tray. Even though I had a bad plug, they all came out easy.

I replaced them with the Bosch glow plugs.

 

[M923driver]

I'll second the recommendation on the 60G's. All 8 are accessible without too much difficulty with a deep socket. Be sure of a good connection where the terminal crimps onto the wire at the GP. I soldered and shrink wrapped them to be sure. I also changed out the relay at the same time to the new style. (round, like the old Ford starter relay) Take your time.

 

[Whitfield]

Solder and shrink sounds like a good idea.

Any tips on where to find the proper spade terminals for the 60g's, as I hear they have a wider terminal then what is in there now.

Finding a retail store with a good assortment of electrical terminals has always been difficult.

 

[cpf240]

Cucvelectric is a good place to start, but as I recall, they are nothing special. The stock glow plug terminal is actually smaller than most spade terminals. I would think that any auto parts place will have them. Heck, even Home Depot should have them.

 

[tbearatkin]

You should be able to access all without removing anything. Yes the back two on the passenger side are more difficult to access but you should be able to get them out.

Now more experienced on here might have a different opinion if they are swollen and if so they will speak up. I unscrew the plug from the block and then turn the engine over just a little and compression will blow them out. I take the pink wire off the IP so the engine wont start.

 

[Whitfield]

Access was not too bad ~ nothing like GM's front wheel drive V-6 cars....

( 8 ) New 60g glow plugs installed. There were only (3) original narrow electrical termainals left. I soldered on 4 new terminals and am now good to go. The GP's that came out looked fresh "Well ~ somthing brand but I was afraid of the risk of swelling.

Almost turn key now. All that is left is a bad GP controler card. No ground signal to GP relay when you tunr the key.

Manual 7-10 sec cycle of the GP relay and she starts right up.


10-29-12 New Controller card from CUCV electric on the way.


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