Glow Plug Harness to Battery connector

[Dave Sponaugle]

I bought a kit off E Bay.
Delphi Weatherpack connectors that are waterproof.
The kit I bought came with crimp tool and a terminal removal tool with a selection of single, two, three, four, five and six wire connectors.
The are not good for big amp connections, but they are great for lower amp connections like lights, sensors and the like.

Not cheap, but electrical connections that are waterproof mean less time repairing the same ones over and over.
Plus they have locks on the connector, so they don't just pull apart with a little snow or ice buildup on the wires under the vehicle.

 

[sassyrel]

Just wait, it will happen they all do it. I do not like those slip type connectors for high amperage connections. When they get hot they expand and that makes the connection even worse. They had the same problem with those 2G alternator connectors melting and sometimes catching fire, and it's the same problem with the headlight switch connectors.

I would keep some sort of connector at that location. It's very handy to disconnect these wires and move them out of the way when changing the valve cover, removing the exhaust manifold, etc. When mine burnt up, my smaller connections in the plug were ok, I just re-used them. The two larger ones that burn up I just crimped 4 ring connectors on the 4 wires, and then used small bolts and bolted them together. That way I could take it apart if I needed to. One of those larger connectors that are used for winch disconnects would probably work fine too.

186,000 and counting.....how much longer????

 

[sassyrel]

I'm not an Electrical Engineer but I do have 60 yrs of electrical experience.
The glow plug circuit consist of: from the battery there are two #10 AWG in parrallel each is protected by a #14 AWG fusible link, from the GP relay to the GP's there is two #10 wires, they split and feed each side of the motor, each GP is feed by a #14 spliced into the #10 wire. The initial current on start of the GP cycle is ~190 Amps for ~1 second, then lowers to ~130 amps, each GP pulls ~16 Amps @ ~9 - 10 VDC, (130 / by 8 = ~16) the max GP cycle is 15 seconds (with a good controlling GPC). The zig zag "Chromolox" strip on the relay is a "resistor", it controls the in rush current and as it heats up controls the voltage and current to the Gp's, as the GP's heat up, the current and voltage is reduced to each GP.
A fusible link wire is a special wire with special insulation, if an overload current accures, the wire will seperate (melt) within the insulation.

To defeat it's purpose (original circuit) by using a large Fuse (250) Amps is not a good protection, a 150 Amp Slo-blow fuse would be adaquate in place of the fusible links.

By increasing the wire size, that allows a higher current to pass in case of a short to ground (Neg side of battery) for a longer period of time depending on what the wire is protected by.

The reason for the OEM connector melting is that the contacts within the connector become corroded and cause a high resistance which creates heat at that point.
That can be expected after 25 - 30 years. So renewing the connection there by new connectors or splicing, you should be good for another 25 - 30 years.

yeah,,and your replies,,dont beat others over their head, either.......thanks.....

 

[Wvdirtroad]

Well I picked up some number 4 welding wire. I may give that a try.

 

[franklin2]

Well I picked up some number 4 welding wire. I may give that a try.

I agree with what was mentioned before about keeping the stock double 10 gauge wires. I know people do it all the time, but the glowplug controller on these things is touchy. Any additional voltage from a larger wire with less voltage drop could cause it to act differently. Like I said people have done it, and I think someone said the later trucks may have had a single larger wire from the factory, but I would keep an eye on the cycle times if you do use the larger wire.

 

[Wvdirtroad]

I will definitely keep that in mind. When I pulled my harness wire put it appears to be running on a double wire that crimps to one terminal at each end, and it seemed like it was maybe 8 gauge. Not 100% sure though. I plan to be more careful now anyways since I just installed new glow plug connectors and heat shrink on them so I don't want to fry them like someone fried the old ones! While I'm at it I may just go through and replace the positive battery cable like it needs now and then also replace the starter, as I'm sure it's probably cooked too. I'll know more when I see how quickly the truck starts with the new injection pump.

 

[Wvdirtroad]

Pictures just because I know I like them when looking at threads.

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[Dave Sponaugle]

All the IDI motors had two 10 AWG wires from the factory.
The single larger AWG wire feeding the controller were on the Power Stroke.
Power Stroke glow plug system is a whole different animal that what was on the IDI.

 

[Smcattle]

I am having a little different trouble with my 7.3 idi. Even with the key off if the wires from the battery to the glow plug relay are hooked the thing just keep heating up to the point where the whole zig zag piece on the relay glows red and smokes until I pull the cable off. I thought my yellow glow plug wires were bad and they are in rough shape so I tried to bypass them temporarily to get home even then it wont stop heating up as long as the battery cables are connected. I really hate having to ether this truck to start it. What is causing it to have constant voltage there? Shouldn't there only be voltage for a few seconds?

 

[Thewespaul]

Can you post a picture of how the solenoid is currently wired? If it’s all correct then the contacts are welded shut

 

[franklin2]

Take the white wire off the relay. If it still has the same problem, your relay is definitely welded shut.

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glow plug controller

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[Macrobb]

All the IDI motors had two 10 AWG wires from the factory.
The single larger AWG wire feeding the controller were on the Power Stroke.
Power Stroke glow plug system is a whole different animal that what was on the IDI.

I know this post is really old, but I want to make sure that everyone knows that this is wrong. OBS IDIs(92-94) use a single main power cable to the GP relay from the power distribution box on the driver's fender well.

 

[DrCharles]

1993 factory schematic. Although there are two fusible links, I'm not sure where they're fed from. At some point they must be two separate wires since the fusible links are separate. But they do join to make one large (red) cable going to the GP controller.

 

[Macrobb]

1993 factory schematic. Although there are two fusible links, I'm not sure where they're fed from. At some point they must be two separate wires since the fusible links are separate. But they do join to make one large (red) cable going to the GP controller.

When I pulled my last couple of OBS motors, I found a single lead mounting to the fuse box on the driver's fender well(remove that nut to pull the engine+harness) Not sure if there's two wires feeding that from elsewhere, but they don't go through a plug to the engine unlike the bricknose trucks.