When starting my 002 the wiring harness from the control panel to switch box melted down from some type of short?

[Philratcliffe]

One of my die hard mep 002s melted the wiring harness that goes from the control panel to the switch box. It fried the harness and the center plug that goes into the back of the switch box! The unit never started, doesn’t seem to have damaged anything in the switch box or the control panel I have an old switch box I removed the plug and harness for the switch box and am looking for a used harness I think delks will have one. I’m worried the same thing might happen after replacing the harnesses. What might have caused this? I’m also changing out the starter to make sure it isn’t the culprit. Thanks in advance for any insight to the cause of this meltdown!

 

[DieselAddict]

What comes to mind first is rodent damage. Do you have any signs of little furry friends?

 

[Guyfang]

It probaly didnt happen over night. So try writing what happened. The whole story, don't leave out anything. We need to know what happened, to try and figure out what might have happened.

 

[Philratcliffe]

I live on an island and they have been running 24/7 most of the time. A couple months back I had a problem with the 1 phase 3 phase switch so I bought a pair of government rebuilt switch boxes. I installed one on this unit and it was running fine. No on rodent damage. I have 3 mep 002s. And two of them run 24/7. This unit I recently put a set of rings and bearings in and was using it several hours a day to fill scuba tanks and to run some small hand tools and saws etc for my workers. All the wiring inside the switch box is fine. The Bakelite insulator in the femaleside or switch box side is cooked like carbon. The first seven or eight inches of the male plug side of the cables are severely burned. I have probably 30k hours on this unit. I don’t run the oem starters. I can’t get repair parts for them so I run the reduction style that they sell on eBay and Amazon for just over 100 dollars. I’ve had good luck with the starters but the selenoids are junk and don’t live very long but I can get them locally for 30 dollars. I pulled the female half of the wiring harness out of the old box with the problematic 1phase 3 phase switch and just bought a control box harness from
Delks for 150 which I hope to have in a couple weeks. Just want to figure out the root cause so it doensnt happen again after I replace the harnesses. But zero rodent damage the cables are in great shape other than the burned up section. These china starters have a bracket on the rear to hook the ground cable to, but a local starter shop rebuilt it and I got it back missing the little bracket for the ground cable. So my mechanic connected the ground cable for the Battery to the rear mount where the ground strap is located. The original ground strap was in very poor condition so I made one out of 0 gauge battery cable and two large crimp on copper ends which are also soldered on. I’m thinking of this as I write this. Mechanics in Latin American countries don’t seem to get the bolt stretch deal on torquing fasteners so I’m wondering if maybe the bolt thru the battery cable end and the ground strap might not be tight enough. Do you think it’s possible that I didn’t have a solid ground and that the generator tried to used the wire harness to ground the starter? We have been using it like this for well over a month since we re rung the engine. In the am
I will put a wrench in the ground bolt and see how tight it is. I thought the wiring harness only supplied 24v current to the starter selenoid am I wrong? Could it have used the harness as a battery ground cable? Thanks in advance for your opinions

 

[Guyfang]

So when did it happen? By start up? or while running?

 

[Philratcliffe]

On start up. I checked the bolt grounding the battery to chassis ground and it’s good and tight. Don’t see any damage other than the cable! This thing is 38 years old. So maybe the plug founded itself and fried the cable.

 

[Guyfang]

On start up. I checked the bolt grounding the battery to chassis ground and it’s good and tight. Don’t see any damage other than the cable! This thing is 38 years old. So maybe the plug founded itself and fried the cable.

Take a picture of both ends of the cable. The thing worked, so grounding itself dosnt sound right. Take a look in the AC box. Is something burned up there also?

 

[Philratcliffe]

Take a picture of both ends of the cable. The thing worked, so grounding itself dosnt sound right. Take a look in the AC box. Is something burned up there also?

The ac box looks perfect. The cables inside the box look perfect also. The ac box is a fresh rebuilt from the military, I bought two of them.
I will take some pics in the am. It looks isolated to the plug and the first six or seven inches of the control box side of the cable.

 

[Philratcliffe]

The only reason I have to change the control box side of the cable is because the backlite separator inside the female half of the connector is fried. It looks like a fun job. I had to gut my old ac box just to remove the female plug and cable !

 

[Chainbreaker]

Not directly related to your problem...however since you have 3 MEP-002a's you should verify they have this wiring mod as it relates to the starter:

 

[Philratcliffe]

Not directly related to your problem...however since you have 3 MEP-002a's you should verify they have this wiring mod as it relates to the starter:

I can’t get the link to open. I’d like to read it! I’ve had these 002s for 5 years with one running 24/7 and now have two running 24/7. Swapping over to my four new to me 005s. One of them should take care of my electrical needs for a while. I plan to sell my 002s. Just want to repair the one the burned up the cables. They have been incredible machines. Easy on fuel and I change the oil every 175 hours they have 25 and 30k hours on them. I just went theough one that was down on power and I only had to ring it after 25k hours! I threw rod bearings in it too the mains were perfect! I couldn’t believe the condition of the cylinders and bearings after running so long! I hope the 005s are as tough.
I can’t get the owl starter parts down here so I’ve been running those cheap gear reduction starters they have on eBay for 110. Bucks the seleniods don’t last but at least I can get parts for them. They don’t put as much load on the battery as the original direct drive starter but those own starters are tough as hell and don’t get nearly as hot as the reduction type.
Thanks for the link!

 

[Guyfang]

When you click on the link, it goes to downloads.

 

[Philratcliffe]

Thanks guyfang. I will download it with a laptop