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As my truck was cranking over this morning, I witnessed smoke coming from under the hood and a burning electrical smell. It started up just fine though, so with it running I go check under the hood and see two fried wires that used to connect to my starter relay.
So according to my '87 electrical and vacuum manual, these two wires run to my glow plug controller. They become the two yellow wires that you see hooked up to the GPC.
Thats as far as I got though. Can anyone weigh in on what happened? I am tempted to splice the wires back together, but maybe something is bad with my glow plug controller that caused that?
those are 14 gauge fusable links.
they act as a fuse and will burn like that when there is a short in the system. you will need to find out what shorted out before replacing them otherwise they will just burn out again.
if you do not replace them and just twist the wires together, then the whole wiring harness will burn up, and probably the truck too.
Thanks for the info. I've never located a short before. Is it something I could find with the naked eye, or do I need to rely 100% on a multimeter? Also, is the short definitely going to be between the g plugs /gp controller and starter relay, or might it also involve my ignition switch?
Ok, I got it. And I am assuming you're referring to the fuel shutoff solenoid. I'm going to go out and have a look when it gets lighter outside. Fingers crossed for an obvious problem, thanks!
Man, I have to get this truck up and running again- shes too important to me to just be sitting there with two toasted wires.
Its been a long time since I've had a chance to work on this. I replaced the fusible links back in November and also saw this:
This is where the wires from the starter relay meet the wires from the glow plug controller. They are hot, melting, and probably touching in there and causing my short, wouldn't you all agree?
My question is what to do about it? They don't make this part anymore, do they? My web searches have turned up nothing. Do I have to re-wire from my GP controller to relay? Thanks!
I had the same thing happen I just cut the wires on either side and soldered them together and put shrink tube over it, remember to put the shrink tube on before u solder and slide them away from where ur soldering while u solder. I forgot about three times in a row lol
Same thing was happening on my '88 with that wire connector. I just used butt connectors to splice the two glow plug wires together. The rest of the wires going into the connector were in decent enough shape to be left alone. They are just long enough to fit when the connector parts are clipped off the and insulation cut back.
This is a known issue with our trucks, the amperage going to the glow plugs is too much and melts that connector. While its possible the short is there, I would keep looking (but do fix that connection).
This is a known issue with our trucks, the amperage going to the glow plugs is too much and melts that connector. While its possible the short is there, I would keep looking (but do fix that connection).
Yep, definitely a known issue. One of the first things I had to do when I got my pickup. I also cut the wires off the plug and connected them outside of the plug and taped over them to keep dirt and moisture out.
Open the plug and see how bad the damage is. If it's bad enough, maybe one of the yellow wires melted into a ground wire and shorted.
If/when the fusible links burn in my truck I will replace them with a blade fuse type, I wouldn't just solder them back together.
As fas as the plug just go to a junkyard and get one out of a newer vehicle, or buy a new connector with the right amount of wires.
Last edited by ConstantProject; Mar 6, 2015 at 12:56 PM.
Reason: added more
There isn't a ground wire in that connector to short to. More likely is that there is one or more shorted glow plugs, and when the contactor engaged it cooked the wires.
Since my engine was hurriedly swapped into another truck, I don't even have that plug. The two glow plug wires go to the battery through a 150amp mega fuse, and the FSS wire is hooked up. That's all that is truly needed to makes these run, the fuel heater is non functional and I'm running a canister filter so no WIF light either. Mechanical gauges and it's all good.
I soldered the two yellow wires to the black/orange wires and all is well- almost!
I need to check my GP's for burnouts and shorts still, something is still going on with this system.
1. My FSS is not clicking repeatedly when I turn the key to ON. I'm used to hearing click-click-click-click as my GPs are heating up, pretty sure thats the FSS.
2. When I turn the key to ON, wait to start light comes on, but no buzz sound anymore / sometimes it buzzes
3. After wait to start light turns off, I turn the key and just get a click. This has happened in the past and if I wiggle the clutch a bit or push it harder then it will turn over. Seems to be happening more often now though.
After all that BS, when its warm it fires right up. Today was only just the first day I got it running in 4 months though, so we'll see how tomorrows cold start goes. First start today involved about 10 seconds of cranking. I immediately went to get fresh new fuel and then on a 12 mile drive up to 65 mph. Shes running great. I dont think I'm out of the woods yet though.
NOTHING should click repeatedly when you turn the key to RUN. The GP relay should click ONCE, and stay energized for several seconds. After it clicks off, it may click on again after starting (afterglow), but the cycle is not several seconds. The FSS MUST be on at ALL times the engine is running. Otherwise the IP doesn't fuel the injectors.
The rapid clicking you were hearing before was probably a result of the problematic connector. The fact that it's not clicking rapidly now is a good thing.
A GOOD GP relay shouldn't buzz.
The no-crank issue you describe is a result of the awful design of the clutch safety switch. It's supposed to be self-adjusting, but it's something of a joke. I've just found that I have to find the right "sweet spot", with the pedal just a wee bit off the floor, to get the switch to close and energize the relay.
The FSS clicks once when the key is turned on, and then clicks off when the key is turned off. The glow plug relay in afterglow mode is a slower clicking.
If the clutch safety switch is malfunctioning it could be failing, or might not be on the pushrod quite right. It is easy to disable by jumping two of the wires (I believe the center ones on the electrical connector), but that could also cause an issue if your truck has cruise control. Not to mention the obvious safety issue if its disabled.
