powersltc Posted July 30, 2023 Share Posted July 30, 2023 2004 Monaco Executive, Ron P. There is a plug of some sort with wires coming from it on the back of my engine, cummins 500 ism. I have attached pictures. Does anyone know what this is and why it would be wet with oil. Link to comment Share on other sites More sharing options...
BradHend Posted July 30, 2023 Share Posted July 30, 2023 Have an overheat condition recently? Is your crankcase breather tube in around there, and do you by chance have an exhaust leak? Odd that the harness would be melting like that. 1 Link to comment Share on other sites More sharing options...
Ivan K Posted July 30, 2023 Share Posted July 30, 2023 When you say back of the engine, you mean the pulley side, right? This is a pass through connector into the overhead valve cover area, it has leads for your Jake solenoids and more. The only sure known way to stop the seepage is to replace the harness with it's connector, not cheap. Mine leaks a bit too and I just clean it and live with it. The breather tube is on passenger side valve cover and goes down in the fuel filter area. Just make sure is isn't plugged but if it was, you would have more leaks. 1 1 Link to comment Share on other sites More sharing options...
BradHend Posted July 30, 2023 Share Posted July 30, 2023 (edited) I was more thinking that the breather tube may be melted and leaking along with that harness from say a manifold leak, but I’m not sure which end of the engine that connector is located on. Front/rear have different meanings to different folks. Takes some seriously abnormal heat to melt that wiring harness. I’d also be taking a good look at your radiator and CAC, the fan will blow that oil into the fins and dust and debris collect and clog it up. Snowball effect Lol. Ask me how I know about that particular situation.… Might add, Amazon sells some good Velcro adhered heat wrap for wiring harnesses. You can see I utilized it in the picture there. Works good. Saved that harness from the manifold leak right beside it. Edited July 30, 2023 by BradHend 1 Link to comment Share on other sites More sharing options...
powersltc Posted July 30, 2023 Author Share Posted July 30, 2023 Ron P. The plug/harness is not melted, just wet with oil. Link to comment Share on other sites More sharing options...
BradHend Posted July 30, 2023 Share Posted July 30, 2023 (edited) @powersltc I would have sworn that harness looks melted had you not stated otherwise. I guess you can ignore my comments regarding said. Edited July 30, 2023 by BradHend Link to comment Share on other sites More sharing options...
Rikadoo Posted July 31, 2023 Share Posted July 31, 2023 My curiosity is different in that i would want to see what the INSIDE of that connector looks like. The reason is back in the day there were issues concerning components that had liquid under pressure “ABS, or transmission, or oil pressure sensors” that used “water tight” snap together connectors, that would start to leak inside the cavity of the plug, an that the liquid would be forced to travel between the wire and its inner side of the insulation. Often it would travel to other not sealed locations like electronic modules, fuse boxes or a non factory wire repair, that aside from the mess it would start to swell and fail insulation around other wires, short out modules even drip on your shoes while your driving. If you find the inside of the cavity of the plug is wet you need to determine which connector it is originating from as it may be inline to multiple connectors that are daisychained to several others not only being messy but raise havoc with other electronics. 1 1 Link to comment Share on other sites More sharing options...
powersltc Posted August 9, 2023 Author Share Posted August 9, 2023 Ron P., 2004 Monaco Executive I recently asked about a plug or connector that was located on my engine as I face it. It is a cummins ism 500. I am trying to determine what it is. I have circled in red. Ot looks like a wiring harness of some kind. Please advise. Link to comment Share on other sites More sharing options...
Ivan K Posted August 9, 2023 Share Posted August 9, 2023 Already answered above, what else you want to know? Link to comment Share on other sites More sharing options...
powersltc Posted August 9, 2023 Author Share Posted August 9, 2023 I trying to find the name/nomenclature of the component so that I can find out what its purpose, cost, installation, etc. Link to comment Share on other sites More sharing options...
BradHend Posted August 9, 2023 Share Posted August 9, 2023 Quickserve is of no help? Link to comment Share on other sites More sharing options...
FLynes Posted August 9, 2023 Share Posted August 9, 2023 Is that connector part of the Centinel Advanced Oil Management System? Link to comment Share on other sites More sharing options...
Ivan K Posted August 9, 2023 Share Posted August 9, 2023 For my 1999 built ISM the part number for internal harness under valve cover (the one that shows your leak) is 4022870, Engine control module harness. Not available from Cummins but there are alternatives or maybe some old stock. It could leak around the connector (fixable) or through it, depends. Just would need to confirm the correct connectors. Six connectors for injectors, one for Jake, like below. I don’t recall if the Jake casting blocks access to some of the injector connectors, hopefully not. 1 1 Link to comment Share on other sites More sharing options...
Ivan K Posted November 2, 2023 Share Posted November 2, 2023 Old ISM related post but maybe it will help someone. I had the same connector leak for years and it did not bother me enough to open the motor but since I am running the overhead right now, I ordered a new harness to replace at the same time. Box says Genuine Cummins (or a really good looking fake, made in China of course) and only $89 on ebay. The shop labor would be much more than that, I'd bet. 1 Link to comment Share on other sites More sharing options...
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