My E320 has an intermittent fault. Sometimes the lights don’t work, The battery goes down to 20 %. Trunk lock quit (key still works) . The door locks quit when power goes down. When connecting the battery, I get arc’s on both the positive and negative sides. Need help troubleshooting. Suggestions?

 

Hello and welcome to the forum! Have you checked the alternator? Sounds like your battery isn't holding a charge. If needing to replace it, take a look at the link below to a DIY tech article from our site. Let us know if you have any other questions or if we can assist with any future part needs.

https://www.pelicanparts.com/techart...eplacement.htm

 

Installed a new battery. No help. Taking it to a local repair shop Thursday.

 

But did you check the alternator that charges the actual battery? The battery wasn't necessarily the issue.

 

Alternator checks good.

 

The mechanic at Hi-Tec Automotive in Okeechobee Florida says the problem was in the module under the rear seat. All the circuits I was having problems with were going to this module. He said corrosion was the problem. Probably caused by the leaky sunroof fixed last year.

 

Gotcha, that makes sense. Are you able to replace the module?

 

The mechanic ordered one as well as the harness from the used parts world. Should be here this week.

 

Glad to hear that you got everything resolved. If you have any tech questions or are in need of any parts in the future, please don't hesitate to reach out.