I just started having issues with battery draining over night. Now with a fully charged battery when i turn on the power i dont hear my fuel pump anymore. So i started checking for a short and the method i used points at my ECM. How can i be 100% sure before changing it?

 

Are you saying the ECM was killing the battery?
AFAIK, the ECM has no connection to the battery with the switch off. Keep looking. How are you testing?
PS— if you’re saying all was well before battery was changed, and now it’s not, either battery is no good or maybe wires got crossed? Need more info.

 

some ecu's do have power to them all the time but drain is in the micro-amps. this is necessary to keep the volatile memory active. without this, the ecu would be in constant relearn on power up. if it doesn't have it, then no need. what machine are you working on, the schematic will tell.
i am curious like mr. j what method did you use? to kill a 17ah battery over nite is a big drain and should have a big tell or multiple issues.

 

2008 883 Sportster L is what bike I have. Battery is brand new, went to ride one day and noticed I have no brake lights, so the shop that had done all my previous work came and picked it up. Said the brake light switch wasn't adjusted right for front brakes, and rear brake switch was bad. They said they fixed it, went to pick bike up and had trouble starting it. Got bike home, next day went to start bike and it was completely dead. Hooked it up to battery tender left it on until battery full charged (overnight). Rode it after battery fully charged. Parked bike, and the next day, battery dead again. Charged it again, went and rode that day. Parked it for a few days due to weather. Went out after weather passed, fired right up. Noticed hand grip on left side was loose, went thru and snugged up everything that was loose and went to ride and no turn signals, no brake lights, but head light work. Went to looking under seat and noticed a bare wire on the turn signal module the shop had installed previously, pulled loom off wires to get a better look, and noticed that were they had put heat shrink on the wires, they had all melted together. Called shop, they came and picked up the bike and the owner of the shop called me and said that the wires were smashed. You can see in the photo I attached that the wires are melted. They put the bike back together and informed me that they would not touch my bike again. (Have spent over $4000 at this shop having a frame swap done and reworking the bike.) Get bike home again, and battery is dying over night when it is on bike. Fully charged battery off of bike and left it off of bike overnight and it maintained its charge. Lights are working now, but fuel pump does not kick on when you turn bike to on position, but bike does start. The red key stays lit on the speedo after I remove the key. Turned the bike back on the red key disappears. Turn key back off again, and key disappears. Bike does have a a Pentastar-xp turn signal/brake light system module and Vance and Hines Fuelpak FP3. If I missed anything, just let me know! Thanks for the replies. I followed steps that someone had previously posted to try to determine what the drain was, and it showed the ECM to be the issue. The steps I followed was to disconnect the positive battery cable and run a test light from the positive battery cable to the positive battery terminal. The light stayed lit up and then I removed fuses one at a time and the ECM fuse was the only one that caused the light to go out. Don't know if this is a true test or not, that is why I am asking for help,

 

is this an hd shop?? if so, contact hd directly and setup with factory rep.
independent? probably your word against his.
so it looks like you will be doing some wire repair.
if you have evidence of his fault, there is always small claims court.

 

The shop is a independent and they are slowly hanging them selves. I'm trying to figure out this issue before it causes any more problems.

 

FYI there is a bulletin on XL's of that vintage for water getting into a relay and killing the battery by cycling the IAC motor with the bike off. Symptom is a dead battery and a little whirring noise with key off.

Also, Stevie Wonder could see those wires are melted.

 

 

Wait - did they use liquid tape?