Sparks on Jumper Cable on MEP-002

[mrcarman]

Need input on a technical problem. I'm getting sparking on one side of the short battery jumper cable where it attaches the two batteries together terminal. I'm getting it just on one side where the jumper attaches to the battery terminal. It was starting fine before with no sparking issues and now there are still no issues when I prime or preheat. But when I try to start it, it sparks fairly significantly where the jumper attaches to the battery terminal and then goes dead. If I monkey with it a bit, I get power again for priming and preheat but it sparks again and fails when attempting to start. My first thought was a short of some sort but not sure why all works fine when I prime or preheat. The sparking seems to be starting to melt the battery terminal. Any ideas?

 

[steelandcanvas]

Are the terminals tight?

 

[sewerzuk]

Yep...it is simply a loose connection. There is no short...the battery terminals just need to be cleaned.
Best thing to do is to remove the cable completely, and use a terminal brush to clean both the battery post and the inside of the connector. It is common for a thin layer of corrosion to form inside of those connectors, and the high resistance connection allows a limited amount of current flow. Enough to run pumps and preheat, but when you try to pass the high starter current through it it forms a large arc. It can actually melt the post down into the battery case, if you're not careful.

 

[mrcarman]

Cool. I'll clean and reconnect. Tha is for the help.

 

[steelandcanvas]

Have you dowloaded the TM's for your genset?

 

[mrcarman]

Yeah. Is this issue in troubleshooting or somewhere else in the TM?

 

[steelandcanvas]

It might be, I just wanted to make sure you were aware of the downloadable TM's.

 

[mrcarman]

Yeah, they were invaluable in getting it cleaned up and running.

By the way, I cleaned the terminal and connector and retightened it and it solved the problem. Thanks for the help.

 

[Triple Jim]

I like to put a layer of grease in the joint when reassembling after cleaning. It keeps water and acid fumes out and makes the connection more reliable.

 

[1800 Diesel]

I like to put a layer of grease in the joint when reassembling after cleaning. It keeps water and acid fumes out and makes the connection more reliable.

We think alike--if I have a can handy I use anti-seize compound on the posts and the fastener threads too....otherwise I use grease from a squashed tube of grease that won't go in the grease gun..either one does the job...