Removing/Unscrewing Badly Corroded Smart Box Plug

[Bulldogger]

I was tracking down a flashing Wait light and figured out it was the grounding wire to my Nartron box. What happened is the rubber mounts for the box had crumbled and then let the bolts slack up. I intended to remove the box (batteries disconnected of course) and add rubber bushings all around, then tighten that very loose ground. Trouble is I could not unscrew the main connector for love nor money. I ended up backing out three of the four bolts (all had a loose rivnut and the fourth was inaccessible from the underside to grab onto) and managed to tighten up the ground wire.
How do I unstick the corroded and stuck main plug? I will have to replace the wiring harness end I assume, by splicing in a better one, but I'm at a loss to remove the screw plug without damaging the good box.
Thoughts appreciated.
Bulldogger

 

[springer1981]

I would try a little PB Blaster on it and let it soak in. Then a light grip with channel locks to loosen. Might have to try working it back and forth. If it doesn't work the first time add more PB Blaster. I wouldn't splice in a new end but if you can find a connector you can release the pins one at a time and move to the new connector. Chances are they are good and only the screw piece is corroded.

Post a picture of the connector that is stuck.

 

[papakb]

PB Blaster works well but my preference is Kroil. Another option is 5% ATF in acetone.

 

[Bulldogger]

Thanks. I hit it with PB that night. I'll give it one more try today before I try anything else.
BDGR

 

[Retiredwarhorses]

Not sure about any rubber you speak of, the box is held in via riv nuts. Are you referring the the rubber foam seal
that surrounds the top plug? Here is a tid bit....the bolts provided with the OEM S3 box are too long, this because the bolts are for the newer trucks that would have armor overlay on that part of the truck, using the bolts provided will ruin the rivnuts and the bolts won’t tighten up all the way, 1/4-20x1 work fine.
What plug is stuck? Engine harness side or body harness side.

 

[dhaumann69166]

I ran into that same problem. My issue was the rubber on the wiring harness side, where the wires go into the plug, had corrosion bad but I couldn’t see it. When I unscrewed the plug on top of the box the center pin from the box came with it. I used a dremel tool and cleaned up where the pin sets. Then I took a nail and cut it to the same length as the pin and soldered it in as a new center pin. Everything worked fine for a few weeks until road vibration started to crack the dry rubber put on the harness side. One day working on something unrelated I bumped the wiring harness and the center wire started flowing current to the wire beside it (glow plug wire). I noticed pretty quick from the smoke starting to roll off the plug and glow plug wire.
I spliced on a new end, the wires are soldered into the connectors not pins that you can release, and it’s working fine to this day. Had to replaced my fried glow plugs but still running the nail for a center pin and a spliced on connector.

 

[dhaumann69166]

If you can solder you could cut the old plug off and put a new one on that wiring harness. The connectors have part numbers you can google and get new connectors.

 

[springer1981]

A quick look on epay and they are $45 with free shipping for a new harness. I would do that before trying to fix the old one.

 

[Action]

A quick look on epay and they are $45 with free shipping for a new harness. I would do that before trying to fix the old one.

If you have a PCB that uses that $45 harness, I would get rid of that PCB. So your HMMWV doesn't burn down.

 

[springer1981]

If you have a PCB that uses that $45 harness, I would get rid of that PCB. So your HMMWV doesn't burn down.

It just sank in, that is just a glow plug harness and doesn't use (or wired to) the temp controller. Thanks for the education.

 

[Bulldogger]

Well, another go with my big Channel lock pliers and it won't budge. I am going to have to shore it up best I can and when the time comes it HAS to come apart a saw will be involved I fear.
RWH, you are spot on, the bolts were tight but the threads are not down the entire length so they stop before the box is tight. I replaced three of four, as I couldn't get anything on the spinning nut on the back side of one. I got the ground wire good a tight and put some sealant on the top of it to try to keep rust out (also switched to stainless bolts).

I will give it a try this evening, can't get away from the computer just yet today and this weekend was lost to kids coming and needing supervision and a honey-do list a mile long.

Thanks all for the input and advice.

Bulldogger

 

[badgerd]

When these get REALLY bad (as all connectors will eventually) we break off the threaded ring and slowly work out the connector body from the receptacle. That takes patience and a screwdriver but can remove it with little to no damage to the mating connector.

Just another idea if it needs to be replaced anyway.

 

[Bulldogger]

When these get REALLY bad (as all connectors will eventually) we break off the threaded ring and slowly work out the connector body from the receptacle. That takes patience and a screwdriver but can remove it with little to no damage to the mating connector.

Just another idea if it needs to be replaced anyway.

Thanks badgerd, I will keep it in mind.

I double checked my meager fixes, all wiring, and then reconnected the batteries and she fired right up and performed the glow cycle without issue. Several other maintenance items to perform, but glad the flashing light went away.

BDGR

 

[Bulldogger]

The flashing Wait Light came back shortly after I jinxed myself by posting the preceding update. Life took over and I had to put it aside until this week. After a few more days of testing glow plugs and tracing wires, I managed to clear the fault by removing and cleaning the glow plug controller connection, but I wonder when it will come back. Ugh.
BDGR

 

[Retiredwarhorses]

Fast flashing from EESS means the EESS does not see the TSU, unplugging it and plugging back in usually fixes it.

 

[Bulldogger]

Fast flashing from EESS means the EESS does not see the TSU, unplugging it and plugging back in usually fixes it.

Thanks RWH. That hold true for my issue.
BDGR