The controller will initiate an after glow under under some circumstances. The initial heating will correspond with the "wait to start light" but the "afterburn" will not. The afterburn is to smooth out the idle and reduce white smoke. I have the service manual that describes it in detail. Once the ignition is cycled off and on, the process will start over with the "wts" light coming back on.

 

I understand the afterglow cycle, but that is not what galute is talking about. He never mentions the lite coming back on, or it short cycling (2-3 sec) which is what the after glow does. I read in his post that he sees the WTS light for 3-5, and the ampmeter does not come back up for another 5-6, well that makes 9-11 seconds anyway.

So i guess we need Galute to elaborate on this pre-after glow / post intial glow cycle.

 

Yeah I guess your right, from my experience that controller is not predictable once it starts to fail. Right up to the point where I disconnected it, I was getting the WTS light for 10-12 seconds (I think it was just timing out), but it was not closing the relay whatsoever. It took me replacing to relay to realize it wasn't the problem.

 

I have noticed something like this also. In the morn, the wts light stays on for 12 sec. then turns off. But I have a holley red pump that I can hear (cause its so freaking loud), and I know that the glow plugs stay on for many seconds after the wts light goes out.

 

I have only noticed the after glow working a few times. After the light goes out then about 5 seconds later the guage will come up then briefly up and down a few times but there is no light to correspond to the afterglow.

Here is my routine. Turn the key on. WTS light comes on, voltage guage drops to about 9 volts. About 3 to 5 seconds later WTS light goes out but guage stays at about 9 volts. About 5 or 6 seconds later volt guage jumps up to about 12 volts, start truck. A few times after all that I have noticed the guage going up and down briefly indicating to me the afterglow is working but it don't happen often as it don't get that cold around here often. When that happens the light stays off. The times and voltage numbers I am using are my best guess cause I've never actually timed it and there are no numbers on the volt guage. I don't know why it does this, just know it works and if it ain't broke, don't fix it. LOL.

 

half the time my wts doesnt even light but the glow plugs work. I watch the amp gauge as well. No problems yet.

 

Well in my case it was broke.... I'd rather have full manual control over it anyways..... not risking another 2 hours of labor and $90 in glow plugs.

 

My best guess is I have bad GP's. I've tested 4 of 8 and all read 0.00 resistance with a digital multimeter. I put the black probe on the hex and the red probe on the terminal, the meter started at 1.0 and then sunk to 0.00. I've also lit them up with them pulled out of the block and got no results. As for my controller, it has been shot for some time, I'm sure. The PO (Father In-law) had the controller by-passed with a momentary switch, work was done by Northland Diesel in WA.. I've hooked up a 9.6 volt test light to the furthest front connectors of the wiring harness and found that the light goes on when I press the switch, stays on after the WTS light goes out and turns off when I release the switch, I would assume that the button has total control of juice going to the GP's. If you look at the solenoid on top of the GP controller you will see two large posts and to small posts. The large post opposite of the other large post with the z metal connector has a large awg red wire that goes to my starter solenoid. The lg. post with the z-metal has a yellow wire that goes to the bad controller and at the end of the z-metal strip are two black wires that go to the left and right GP wiring harness's. The small post closest to the cab has a red wire that I believe goes to my momentary switch and from there a red wire that goes to the + side of the drivers side battery with a inline fuse. The small post closest to the engine has a black wire that goes to one of the controller mounting bolts for ground. Behind the controller is a wad of wires that have been all taped together, I believe they are red, white, green, and black, the blue is the WTS light and that was left hooked up to the dash. The reason the WTS light still comes on is because I believe the yellow wire connected to the large post that goes to the GP harness was left on and still sends current to the controller even though its TU. My only confusion is whether or not the relay is good and the GP's are getting the right amount of current or amps. I'd hate to blow $100 in new GP's, because I overlooked something small. Back to figuring out how to work the new multimeter.

 

P.S. to all you ZD9 believers, the bad plugs where 10 year old autolights with 220,000 on them and no swelling!!!!

 

As far as the resistive testing, the continuity test showed that your plugs were good. But if you've got 220K miles on them it was probably time for them to be replaced for age. The PO of my truck had autolites (1008's I think) and all but 1 was burned out. No swelling, no cracking, no pitting, or any other signs of damage but all shot. The one that did work took a good 20-25 seconds before it would get "cherry" hot and it was just for a small section of the tip. Try a fresh set, and let me know how it turns out.

AB

 

I would just try to hold the button in longer. On my truck the plugs glow for 11 sec at 25 deg. outside. Sounds like your plugs are just not getting warm enough. If that doesn't work, then I would spend the cash and get new plugs. The only other thing that could be wrong is that the relay on the controller would be bad. You could check that by putting a test light in a plug socket and hitting your dash switch. If it lights up your relay is good.

 

The resistive test showed my plugs were 0.00, isn't that a dead short. As for the relay, I did put the test lite in the plug socket and it lit when I hit the dash switch and went out when I released it, as stated in the previous post.

 

If it is not a good quality ohm meter it will show o or a dead short.

 

When these plugs go bad you'll typically get and "open" circuit, which the meters will show infinite resistance, but I guess that its possible that internally the plugs could short and bypass the element all together. For several of them to do that would be unlikely though.

Do you know what range our meter may have been set to? If it was in the Mega or Kilohm range, it would diffidently read 0.00 on the display.

Keep in mind that a new set (my ZD-9's) all read .5 ohms or less before I installed them.

When you said you "I've also lit them up with them pulled out of the block and got no results" was that with at test light?

Grab a set of jumper cables and directly connect it the GP (there's a video of it in a very recent forum thread) and see if they light up.

 

16,839 post and finally got a good report on autolight plugs, I belive i'll order some tomorrow. LOL