Guys,

It seriously is not power to the relay, the relay, or anything to do with the relay. It works perfectly. There is good power on the main power cable to the relay, there is power on both sides of the little wires and when the truck finally decides to make the circuit work, it works fine. The PCM for whatever the reason "selectively" grounds the glow plug circuit when it feels like it. I have yet to pull the engine oil temperature sensor as it was -15 out yesterday and very windy at my house which is much too cold to be screwing around with it. After turning the key on for about 2 minutes, the glow plugs (magic?) finally did come on and it reluctantly started. I do appreciate everyone's help. As soon as it warms up some I will pull the OTS and see what happens. Thanks!

 

Look, not to sound like an a$$, but you came here, saying you were having trouble with your glow plug system. Myself, and others have asked you questions to see what you have checked, giving pointers, and things to look at, to try to get everyone on the same page. I have no idea what you have looked at, other then what you have told us. You also then told me, that there was 12 volts ACCROSS the coil of the solenoid. 12v accross a solenoids coil, means the coil should be energized. 12 volts accross the coil, and 12 volts on each side of the coil (in respect to the negative of the battery) are very different.
[/rant]

Sorry if that is arrogant, obnoxious or whatever, but I was trying to help you.

 

RebelChevy,

No need for any apologies. None at all. Like I said in my previous post I appreciate everyone's help. When it is acting up, here's what I have. The large feed from the battery has battery voltage with almost no drop whatsoever from the battery to the relay. The two little guys on top of the relay have battery voltage going to each of them. From little pole to little pole is 0 volts. The large power feed going to the glow plugs has 0 volts.

Now here's the kicker. The glow plugs do eventually come on. Basically, this is what happens: you turn the key on and you can tell by looking at the battery voltage that the glow plugs are not heating. Then, if you just leave the key on for about 30-40 seconds, they magically come right on, battery voltage drops accordingly to the load being pulled by the glow plus, and she starts right up even when it is very cold out. When testing it in this situation, both the heavy power feeds at the relay have battery voltage, one of the little wires has battery voltage, and the other shows zero volts. I have been told that this is a normal condition.

Here's what I have done: It has brand spanking new batteries in it and they have very good cranking power, a brand new Ford GPR, and all cables and connections seem to be in excellent condition. I am going to pull the connector to the Engine Oil Temperature Sensor and see what happens sometimes today as it has warmed all the way up to -3 outside and I might be able to work on it for longer than 2 minutes. From what I have been told, this will put the truck in a closed circuit mode that will turn on the glow plugs. Once again, I do appreciate all the help I get.

Tim

 

Update:

I pulled the plug off of the Engine Oil Temperature Sensor which made the SES light come on and it ran horribly. After reading up on this I thought that it might. But, still no immediate glow plugs. With waiting 30 seconds or so, you hear the click, and then they are on. So, it does exactly the same thing.....It is getting close to time to go to the dealer. But first I will check all the grounds to make sure that they are clean and tight.

 

Thanks to those that offered to help. I am out of ideas so I am taking it to the dealer tomorrow. I will post what they find.

 

You could just remove the ground wire going to the PCM from the relay and hook up your own momentary push button to control the GP's. That also keeps them from coming on when you dont need them in the summer.

 

I like the push button idea. That way you could not accidentally leave them on like with a regular switch.

 

twags and tdpower-

I am thinking that it a good solution. I just may do that. Thanks for the tip.

 

Update:

It is fixed. Thanks for the help guys! The brand new Ford GPR tested fine on the work bench, but when you installed it and tightened down the little field coil screws its operation became erratic. I put another new GPR in it and it works fine now. Who wouldn't have thought a guy would be so unlucky to get a bad GPR right out of the box? Once again, thanks for the help

T. Bauer