7.3 IDI glow plug controller

[RAPATC]

My 7.3 IDI had a new glow plug controller and glow plugs installed back in June. Recently when I would go to start the truck the glow plug light would
not come on and the truck was difficult to start. This is now happening on a regular basis. It turned cooler and I started to plug the block heater in. I am
in Northern California and the temperatures haven't gotten below 25 degrees. If I go to start the truck after the block heater is plugged in the glow plug
light comes on and goes out after a few seconds and the truck starts right up. Today when I left work it was 55 degrees out and I had trouble starting the truck.
Is there a short in the wiring that is causing the glow plug controller to activate only part of the time or could the glow plug controller be failing already after only 6 months?
I am at a loss and can't figure out why the truck seems to operate normally after the block heater is plugged in for a couple hours. The wiring under the hood is a
mess even after I spent $2200 dollars at a supposedly reputable shop this past June. Any help or insight that you guys can provide will be greatly appreciated.

V/R,

Paul

1985 Ford F-350 CC Dually 4X4 7.3 IDI with Banks Turbo and ZF 5 spd.

 

[DaveBen]

Did you try to cycle the key a couple of times before you started it? New glow plugs by your 'reputable shop' may be cheap replacements. You should use ONLY Beru or Motorcraft glow plugs. The others are junk. I know the Redding area temps and they are not unlike what we have, plus or minus a few degrees. All of this sounds like your glow plugs are not ALL working. You can test them with an Ohm Meter. You should get about 1 ohm from the tip to the chassis (ground). Good luck Paul.

Dave

 

[FORDF250HDXLT]

that's what happens typically on the latter systems Paul,when you've got a glow plug or two that has burned out.the system will no no longer glow the rest of the plugs for the full duration.it will simply flicker.
you can test them easily with a test light.for more diagnostics:

http://www.oilburners.net/forums/showthread.php?75157-diagnostics-for-the-87-94-glow-plug-system

oops.slow typed that one i guess.
so like Daveben says.

 

[RAPATC]

Dave,

Thank you very much for the information, That is what I was afraid of that the glow plugs are bad or going bad already.

 

[RAPATC]

Mel,
Thank you for the quick response and information. It looks like I am changing a set of glow plugs.

 

[franklin2]

You can check the glowplugs with a meter or testlight to see if they are good. The should ohm out very low from the connector tip to ground if they are good, or you can clip a testlight to the battery + and then touch the tip of the glowplug and if the testlight lights up it should be good. Just make sure you unplug each glowplug from the harness before testing.

If you find they are all good,, then plug them all back up and you may find it now works. If that's the case like mine, your connections on the glowplug tips are not good. Mine would work fine for a couple of weeks and then do it again. All I had to do was go out and unplug and plug back in each glowplug, and it would be good for another couple of weeks.

 

[riotwarrior]

As above...test...report back...beru are only plugs worth while.

Does invouce indicate brand of gp?

What is shop name?