Truck won't start - need some help

[Doc]

I replaced my glow plugs yesterday and Big Red fired right up afterward. This morning I couldn't get the truck started to save my life. I notice the glow plug controller wasn't cycling like it normally did. The light went out after about 6-8 seconds, but the click-click of the solenoid was missing. I thought maybe the controller had gone bad so I replaced it this morning. Still nothing.

There is roughly 25.4 volts going into the controller. On the glow plug side of the controller the solenoid shuts off at about 17.5volts and that's it. No cycling, no nothing.

I know all the connections to the glow plugs are good and allthe harness connections are good. Other than that, I'm lost, but I gotta get the truck going for work tomorrow. HELP!!

 

[tonkadoctor]

There is roughly 25.4 volts going into the controller. On the glow plug side of the controller the solenoid shuts off at about 17.5volts and that's it. No cycling, no nothing.

It should start in this warm weather even if there are problems with the glow plugs. May start a little harder. Are you even getting any white smoke from the exhaust to indicate it is getting a little fuel or does it even sound like it's trying to fire, if not at least one of the above you probably have a fuel problem.

What's up with the voltage that high. Prolly fried some of your "NEW" glow plugs. Test them for continuity.

Another thing to check is if it's getting fuel, try cracking your injector lines and crank it to see if it's getting fuel.

 

[Doc]

No smoke at all out of the tail pipe. There shouldn't be an air lock, I drove the truck for awhile yesterday after I replaced the glow plugs. Still, I can't figure out why the controller isn't cycling.

 

[Doc]

Oh, I forgot, how do you test for continuity of the glow plugs?

 

[towcat]

Couple of things.
first, GP's need to be on via controller 10-12 seconds before they start cycling. Any shorter is an indication that you have at least three not working. Start hunting
second, make sure your batteries and cables are healthy. Not enough amps and internally corroded cables is often the start of many other issues. Why do I bring this up? You shouldn't need GP's in TX. In the spring/summer I don't miss them in my truck. Only around fall do I "get around" to replacing them when they do go bad. If your cranking speed is at least 300rpm, you should be able to fire up easily. Any less, your starter is working OT and it takes forever and a day to fire up. check the health of your starter too while you're there. have fun

 

[Mr_Roboto]

Is this a military truck using a 24 volt system? If it is and you used stock 12 volt glow plugs they would have burnt out immediately.

 

[Doc]

No, not a military truck, just an idiot that doesn't know how to set his voltmeter correctly. I've been doing a lot of work at my house and out of habit had the darn thing set for AC current.

Still, no fire from the truck. The wait to start light goes out in about 6-8 seconds and the controller is getting 12.4 volts. On the glow plug side the controller cuts off at 6.9 volts. What settings do I put my voltmeter at to test the glow plugs and how do I tet them? When the ignition is on the glow plugs get to 6.4 or so volts then go to zero when the controller cuts off.

Also, no smoke from the tailpipe when I'm cranking it.

 

[towcat]

have you checked the two 10ga wires yet? Look especially at the connection point of the harness between the body and motor.

 

[Doc]

What two 10 gauge wires and where are they located?

 

[towcat]

I just read your sig. Your system is a little different compared to the 83-91's. You shouldn't have that problem. Yours is on the driver's side near the windshiled washer bottle. The earlier ones have it on the passenger side just foward of the AC dryer can. Irregardless, there is two 10ga wires that feed the GPC. Follow the GPC to the solenoid and they should be there and in good shape. There's also fusible links on the solenoid side that should be checked to make sure you're getting juice and they're not burnt. happy hunting

 

[Doc]

I'm getting juice to the glow plugs, but it's only about 6.5 volts. Are the fusible links in-line with the glow plug wiring and if so, about where might I find them?

 

[sassyrel]

doc--two things---what brand gp's---and--make sure the ground wire to the controller is grounded good----hope you used motorcraft gp's-----

 

[Doc]

I used Motocraft BERU glow plugs. Those were the ones recommended by all you guys. I double checked all my connections an as far as I know they're all good. I need to pull the air cleaner assembly off and look at the fusible links and everything else I can't see with it in the way.

And I have to say, I hate eletrical problems.

 

[kcw12]

Check and make sure its grounded. id run a ground wire to the relay on top,

 

[towcat]

The fusible links are by the solenoid for the starter. Two of them. If only one is good you'll still get voltage but not the amps.