another glow plug prob..

[blaz4wd]

I have been replacing my glow plugs two at a time every pay day from the start of last month.. now I'm having them go out .... what could be making them go out so fast? Is there a sensor that controls how long the glow plugs preheats? 2 days ago it had 3 glow plugs go out..tested all of them with test light. Norm I would have to replace them year/year and a half..they are the zd 9's.... Info on truck. 93 f250 non turbo...4x4 about 215000 for miles.... injectors,injector pump and glow plug controller replaced about 2 1/2 years ago right when the cold snap happens.I Replace the glow plug harnesses to the make your own harnesses last winter. I do run a 50/50 mix of wmo and diesel for the last 2 years. When glow plugs are out they have a sooty look to them.I also run the block heater from 12am-6am and then from 2pm-5pm. Thanks Joe

 

[jonathan]

Sounds like your timing is advanced to much

 

[fordf350man]

how did you check your glow plugs with a test light? i used a dvom and checked the resistance in the glow plug, and there is a glow plug controller that operates the glow plugs, how do you know they are going bad? seems like it should start fine if you have it plugged in to the block heater

 

[blaz4wd]

how did you check your glow plugs with a test light? i used a dvom and checked the resistance in the glow plug, and there is a glow plug controller that operates the glow plugs, how do you know they are going bad? seems like it should start fine if you have it plugged in to the block heater

I checked the glow plugs with the test light. Alligator clip on positive Batt terminal. The touched each glow plug if it lit up it was good. So if it don't light up then that's the bad 1 . When all the glow plugs work the wait to start light / be4 it starts cycling it's about 10-20 sec. Now I'm down to maybe 3 seconds for preheat.

 

[fordf350man]

wouldn't that just show that you have power to the glow plug, it grounds out on the block so that would just mean a good connection from the wire to ground wouldn't it? i dont see how that would show the glow plug is actually good or bad,i would assume its kind of like a coil pack, you can have power to it but that doesnt mean its good, it depends on the amount of resistance it has, i have never been a fan of test lights, try checking the ohms on the glow plugs, i think it should be less than 2 ohms, mine stay on for about 15 seconds but its getting pretty cold were i am, were down to almost 0 degrees, and i live right by the lake so that doesnt help

 

[redneckaggie]

the test light method works but it only tells you whether the glow plug is burnt or working. It doesnt tell you how well it is working. As far as them burning out quickly what is the timing set at?, how did you make the harness?, have you replaced the controller?

 

[jada64]

I have a switch in my cab to run the GPs. But if I have the truck plugged in I do not even need them. 15F and it starts like a gas truck.

 

[blaz4wd]

Ok I decided to redo the wire that runs from the starter solenoid to the glow plug controller.. the write up I'm following says to run New 6 gauge wire and to hook it up to the original fuseable link wire. Why couldn't you use a fuse from stereo amp wireing instead of the fuseable link wire?

 

[crewchief219]

You can, it just has to be big enough to handle the handle the huge draw glow plugs take. I used a 250 amp fuse and 4 gauge cable. Maybe a little overkill on the wire but it works great. I bought my fuse online, from eBay.

 

[OLDBULL8]

You might need this. Each and every glow plug will pull approx. 20 amps for 1 to 2 seconds for a total of 160 amps on the initial start, then quickly reduce to about 5 amps for a 4 to 12 second cycle, that is if the cycle is controlled by the automatic GP controller. The OEM 12 volt supply wires are 14 ga. parrallel fuseible links. The problem with the OEM circuit is not the size of the wire, but the connector, it becomes corroded, and can't pass the the Hi current, consequently it overheats and melts the connector. That being said, the resistance of the fusible link wire and the chromalox Z strip on the GP relay cannot supply sufficient voltage to heat the GP's quickly, which raises the resistance of the GP's to lower the current. So actually the culprit in most cases of the wires burning up, is the connector.

For those that change the wires to a way larger size and oversize fuse it, it's possible to cause a fire. By that, if the GP relay would weld the contacts, the GP's would continually draw current, and the fuse would never blow, that would run the batteries down, possible overheat the supply wires to the starter relay used as a connection point. Even if the wires are connected directly to the batteries, there is almost an unlimited source of current supply from a battery, until it explodes or the source pulling the current opens.

 

[blaz4wd]

Ok so what I ended up doing is keeping the fuseable link wire and replace the main feed with the new wire.. and also put the push button in the cab.. I have to run out and warranty the few glow plugs that are burnt out.

 

[crewchief219]

Sounds like I got some bad info.. I was told in a previous post that it was a 200 minimum draw which is why I went with a 250. Looks like I need to order a new fuse?

 

[redneckaggie]

4 gauge will not handle 250 amps anyway, be lucky to get it to hold 200