New battery and car goes dead sometimes

[mcarman]

I replaced the OEM battery with an Optima maybe 6 weeks ago and occasionally the car goes dead and won't do anything. This only happens when I am getting in the vehicle. This morning I had to use the actual key to open the door and pushed the start button and pumped the brake many times before the electrical system came on. My saved radio stations are wiped out and my seat and steering wheel settings are lost. So it acts like the battery is dead but then comes back to life and works fine. I don't know of a relay that controls power to the whole car. It doesn't act like any battery problem I have ever had. Does anyone have the wiring schematics for an 2006 M35-Sport? Any help would be appreciated.

[mexillis]

Check to see if the connections on the battery post are loose. Also you could have a bad battery, have auto zone test it for you to double check. Look for the FSM in the search box on here and it should have all the wiring digrams you need.

[mcarman]

Turns out the negative terminal was just a bit loose. I swear I had my torque wrench set to max and my cheater bar attached when I installed it.

[myother45isalesbaer]

Whoa! If you put too much torque on the connectors you can break the screws/bolts and or the internal terminal which will short the battery out. You only need to make sure the post and cable is clean and then tighten until snug. Hope you didn't ruin a brand new battery.

[SteveTheTech]

If you put too much torque on the connectors you can break the screws/bolts and or the internal terminal which will short the battery out.

That is possible but highly unlikely. What you would see is if the terminal diameter were smaller by a millimeter or two would is exactly what is noted here, or the 10mm head ends up rounded off. There is a stopping point for the ground terminal which is were most problems start.

As a common practice I give a pretty heavy tug to make sure they are tight. A properly restrained battery shouldn't move when shaken by the cable. You would really be surprised how many people out there have loose, missing, or damaged battery hold downs.

[thomasm35]

I had a similar problem, a new battery and the car would not start at times - it turned out to be a bad Intelligent Power Distribution Module (IPDM) - it is located below the battery on the firewall. It did not have a cover on it and water got into it. The cost at the dealer to solve this issue was $1200.00. The IPDM was $760 and labor $360 --- felt like a screw job to me. Maybe steve the tech guy can validate the honesty of the dealer price.

[thomasm35]

I had a similar problem, a new battery and the car would not start at times - it turned out to be a bad Intelligent Power Distribution Module (IPDM) - it is located below the battery on the firewall. It did not have a cover on it and water got into it. The cost at the dealer to solve this issue was $1200.00. The IPDM was $760 and labor $360 --- felt like a screw job to me. Maybe steve the tech guy can validate the honesty of the dealer price.