Question Constant power to glow plugs?

[Eubee]

Where are you measuring this voltage from?

If you have constant voltage to the glow plugs your batteries will be discharged.......and glow plugs toasted........in a matter of hours.


Lance

***Please note that I an not a licensed electrician, so please correct me if I am measuring wrong***

Measured at the buss bar to GPCM connectors:
-There is continuity from the buss bar side of connector to negative side of battery (each pin in connector checks out with continuity).
-There is ~12VDC from PCM side of connector to negative battery (again, each pin checks out the same VDC)
-Each glowplug ohms out at ~0.1ohm each (removed from head and tested).
-Plug everything in, cycle key on a few times to warm 'plugs, turn key off, quickly remove driver side buss bar, stick finger in hole, 'plugs cold to the touch(?). ...uh oh
-I have a DCA clamp-meter enroute to me so I can check the glowplugs' current draw, so I do not have that measurement yet.
-Charge batteries to 100% (on charger's analog meter), let sit a day or two, put charger back on, charger claims batteries are down to 50%.

Thanks again for any input

 

[Eubee]

Tested this morning: Each bank of glowplugs pulls ~28 Amps (that is total for all four 'plugs in the bank). So if the glowplugs are supposed to pull a minimum of 20 Amps each (min 80A for each bank), I would say I have a problem eh? I dare say this might be why the truck will not start.

 

[DaveBen]

You have several glow plugs that are toast. And your batteries are shot. Get TWO new batteries. Battery problems raise their heads this time of the year, when greater than normal loads are placed on them often.

Your glow plugs should get almost RED hot, at least. It sounds like the GPCM is shot and caused the batteries to go a bad, as well as a few glow plugs. When you replace them use ONLY Beru or Motorcraft glow plugs. All of the rest are JUNK. Go to Ford or International to get them.

Dave

 

[Eubee]

Well, I guess I'll be stopping at the parts store Monday morning.

Thanks for the input.

 

[DaveBen]

I hope this cures it for you.

Dave

 

[Eubee]

Well the GPM is on order from Silverstatefordparts.com ($121.09); as everybody locally wanted full MSRP ($227.XX) or more for the part.

I have a theory that I would like some constructive criticism on. Why could you not ‘bypass’ the glow plug module with a switch? What I mean is like how you activate a farm tractor’s glow plugs. You hold a switch, push a button, or turn the key backwards (I have seen and used these) until the ‘plugs are hot enough to start the tractor, then you turn the key and start the engine. Why could not this be done with the 6.0, or any diesel for that matter? I think it would make a nifty back-up or emergency controller for when you need to drive the truck, but can not get a replacement module quickly. Any help in determining yes or no with this?

Thanks

 

[DaveBen]

Off of this stuff is tied to the PCM (computer) and probably won't work on a switch, as the computer will see an ERROR. It makes it very difficult to do, unless you know the programming and none of us do.

Dave

 

[Eubee]

...WOW!! I ordered the part at aproxamitley 4:30pm pacific time on 06-APR, and it arrived today (08-APR) at 12noon eastern time. Two days to go from Las Vegas to Mount Pleasant Michigan, ...USPS mail even! up:

I just found it in the mailbox (I work thirds and sleep durring the day). So I am now going outside to put the module on and try it. ***crosses fingers***

 

[Eubee]

Well, she still will not start; and on top of that, my backup vehicle is now eating about a gallon of coolant a week. The super duty is getting hauled in at 9am today for a professional diagnosis.

Thanks for the help and suggestions.