Glowplug issue just in time for winter

[ISPKI]

Hey all, of course Good ole' rusty-but-trusty had a hiccup as soon as it starts getting cold. Went to head over to my uncle's last week to take down a tree aaaaaand glow plug controller just clicks with no prime.

Started troubleshooting over the weekend. Started by pull the GP wires off and testing resistance on each plug. All measure ~0.2-0.4 ohm. I even pulled the higher ones to inspect but they looked fine.

Inspecting the harness, the connectors that attach to the glow plugs are toast, insulators are completely gone and the exposed wire is good and crusty. Assuming this is the issue. Ive been meaning to switch it to a turbo harness for a while anyways so I can get my sidewinder back on the truck.

Controller looks pretty clean, still has the insulator cap and tag on the white wire post. Promising.

I made a double shelf over on the fender where the starter relay is mounted and mounted the controller and starter solenoid onto the shelf. I am a little concerned about water dripping on the controller and relays, might build a cover to protect them.

My question, the starter solenoid has a cable connecting it to battery +. It then also has several more ring terminals stacked on the ring terminal from the battery, one of which is a #6? feeding to the power input to the glow plug controller relay. I opted to just connect the Controller relay directly to the battery + post, since it is now less than a foot from the battery. Not sure if there is any reason not to do this except that it puts more cable connections on the battery post? I have 3 cables on that now.

Lastly, I have a blue sea systems MIDI fuse block inline between the controller output and the turbo GP harness with a 40 amp fuse. I calculated 40 amps as being the peak rating for a AWG#6 cable. Right now its just sitting held up by the cables but I feel I should probably mount it somewhere so it isnt bouncing around.

I am going to post up a picture of the new setup so people can critique my methods and offer pointers or ask questions.

 

[ihc1470]

If I am understanding you correctly you have a 40 amp fuse feeding the glow plugs off the controller, is that correct? If so I think you will find it goes **** the first time you activate the system. Those plugs will draw right at 200 amps. As to going to the battery that is OK but I find you have less corrosion issues if you are not connected at the battery.

 

[IDIBRONCO]

If so I think you will find it goes **** the first time you activate the system. Those plugs will draw right at 200 amps.

I just want to add a little bit more to this. Since the controller has been relocated, the wires that run from the controller to the glow plugs themselves will be longer. Longer wires have more resistance than shorter wires do. So, maybe, the glow plugs will be pulling a little bit more amperage.

 

[franklin2]

If you left everything alone, and plugged the glowplug connectors back on the glowplugs, I bet the system would have worked. It's all I had to do every couple of weeks to keep mine going. Those connections get corroded on the glowplugs.

After a few months of doing that, I went to manual glowplugs. No more problems. I can hear the engine missfire once in awhile on a cold start up, some of the glowplugs are not working. But the engine still starts and it quickly clears up.

The others are correct, a 40 amp fuse is not going to hold. And fuses introduce resistance themselves.

 

[ISPKI]

Yeah I was always kinda pondering how this made any sense. If the cable is rated to handle only 45 amps, how does it flow 200 without instantly melting? To be honest, I dont even need the fuse, I still have the links inline. I just used the fuse block to make a safe connection to the harness. I will probably pickup a 200+ amp fuse or just slap a bar of copper in the holder.

 

[ISPKI]

I went to start the truck after and the relay just clicks and doesnt prime the plugs still. Guessing the controller is shot. Need to look into how to evaluate the controller before I go an wire up a momentary switch and cut it out entirely.

 

[IDIBRONCO]

Not trying to dissuade you here, but you can wire up a temporary manual switch. You can bypass the controller that way and see if it starts again. If so, there's your problem. Then you can feel free to keep the manual control permanently or buy a new controller.

 

[Rocknit4x4]

When I first got my truck I had a lot of issues with the glow plug system - turns out my fuseable links failed but only partially. They read continuity, but when the glow plug system was turned on it would only burn for 3-4 seconds before starting to click on and off. Turns out they wouldn’t allow full voltage to get to the controller. Not sure how you came to the conclusion your links were good but it might be worth a double check.

 

[ISPKI]

When I first got my truck I had a lot of issues with the glow plug system - turns out my fuseable links failed but only partially. They read continuity, but when the glow plug system was turned on it would only burn for 3-4 seconds before starting to click on and off. Turns out they wouldn’t allow full voltage to get to the controller. Not sure how you came to the conclusion your links were good but it might be worth a double check.

Yeah, bold assumption. I thought fusible links swell when they fail and/or develop a higher resistance value, but again, I am assuming.

Not trying to dissuade you here, but you can wire up a temporary manual switch. You can bypass the controller that way and see if it starts again. If so, there's your problem. Then you can feel free to keep the manual control permanently or buy a new controller.

Yeaahhhh, I wired up a momentary trigger switch in my last two IDIs and they proceeded to last for years trouble free. Was hoping to get more life out of this controller but I may end up going that route. Pretty sure I have a big industrial button around my shop somewhere.

 

[ISPKI]

Here's a shot of the shelf I made. Hadn't tied up the wires yet so it looks a little jumbled.

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[ISPKI]

Now looking at that picture, I realized that I have the fusible links in the wrong place. The links that went from controller to glowplugs is wired from battery to relay... I wonder if thats an issue... I'll have to switch that when I get home as that should be a big solid cable instead.

 

[franklin2]

The rating for wires can get complicated. Is it in open air? Or is it in a conduit? Is it in a conduit with a bunch of other wires?

The NEC code is fairly conservative compared to what Ford used. You will find Ford regularly used a 10 gauge charge wire on there 40, 60, and 70 amp alternators. Even our diesels I believe have at least a 100 amp alternator, and you will find the charge wire is not much larger than 10 gauge. NEC rates a 10 gauge wire for 30 amps.

The glowplugs are only on for a comparatively short time. That figures into the heating of the wire also. Of course with 200 amps going through a 6 gauge wire(the older trucks had two 10 gauge side by side) you will have voltage drop. But the controller and the rest of the circuit is designed around this, copper is expensive. If you can save a $1.00 on a million pickups you just built, then you have saved a million dollars.

 

[ISPKI]

Aright I sorted this out.

I machined a copper bar and just replaced the fuse with it. Measured resistance from the ring terminal that connects to the relay to each glowplug is 0.1.

Was able to prime and fire up the truck finally.

Only issue is that the shelf I built positions the controller and relay too close to the hood hinge so I went and made an extension tonight and bolted it on. Should pus the controller and relay about 3" into the engine bay. Hosed it down with some paint and will let it dry overnight and mount everything up tomorrow.

 

[ihc1470]

Sounds like the good old days of putting a copper penny under the old screw in fuses. Wires might glow red but fuse would never blow!

 

[HS108]

Glad to see ya got it figured out. Thankfully no snow here yet, but the cold is finally upon us in CT