Battery change out

Reply Subscribe

Thread Tools

Search this Thread

Jun 17, 2010 | 06:58 PM

kennyjohn

Thread Starter

Intermediate

Joined: Jul 2009

Posts: 30

Likes: 0

Battery change out

Does anyone have a way to maintain power for the memory for the ECM when I change the battery??

Is there a way to hook up a 9volt battery through the cigarette lighter?

Thanks for any help

Jun 17, 2010 | 11:31 PM

tedcmiller (Cry Baby)

Banned

Joined: May 2010

Posts: 249

Likes: 0

The cigarette lighter on a H-D, unlike most American cars, is active only if the ignition switch is on. This means that the lights will be on too and a 9 V battery will not last long, if it works at all. A small 12 V battery or battery tender connected to the battery connection that is to be removed would work better.

Jun 18, 2010 | 12:38 AM

CroK

Banned

Joined: Jul 2009

Posts: 3,719

Likes: 1

I wish a 9V battery would help me keep my memory...

Jun 18, 2010 | 07:34 AM

kennyjohn

Thread Starter

Intermediate

Joined: Jul 2009

Posts: 30

Likes: 0

THANKS for the info

Jun 18, 2010 | 07:48 AM

larsfum

Stellar HDF Member

Joined: Jan 2009

Posts: 2,578

Likes: 463

From: On a Lake, not far from the Gulf

Doesn't the ECM retain its memory without power? Thought they were EPROM's. You may lose your radio presets, but that should be it?

Jun 18, 2010 | 07:49 AM

frog13

Outstanding HDF Member

Joined: Apr 2008

Posts: 3,140

Likes: 17

From: Wisconsin

I could be wrong, but I would check with the MOCO on this one. ECMs are programmed with "flash" memory, much the same principle as a memory stick or jump drive. They do not need power to maintain their memory. If that were the case, every battery change or dead battery would require reprogramming the ECM.