2007 G35 Coupe, A/T, 93K miles. Two years into a five-year battery. Car would start strong every time, then turned the key one morning and it barely turned over. Started fine for a few days, then turned the key one morning, the dashboard dimmed and the solenoid clicked. Jump-started the car, checked the battery voltage and alternator output with my DMM - all good. Took it to Autozone to have the system tested. Battery and alternator tested ok, but the starter failed. I replaced the starter. Strong starts for a couple days, then got the dim dashboard and clicking solenoid again. Any suggestions?

 

Battery voltage read at the posts is 12.3V. Resistance from each post to a point where the battery cables terminate is 0.3 - 0.4 ohms. I had previously cleaned the cable clamps with my dremel tool until the metal was clean and shiny. I'm thinking that maybe there's a connection issue in this IPDM I've heard so much about? I guess I'll tear into it this weekend.

 

And now to close out the story: I spent the weekend on this problem. I pulled the new starter and took it in for testing, just on the off chance it had suffered infant mortality. Nope, it was healthy. I measured voltages and resistances at various points in the engine compartment. I dug out the IPDM and visually inspected it. It showed no corrosion, not water marks, no overheating. I had no way to test the relays, but they were clean and showed no heat or water damage. So, I packed it all back up and took it to the garage I trust.

The verdict came back this afternoon: bad battery. Under load it was putting out 9V, not enough to do the job. Something internal to one or more of the cells caused a two-year-old five-year battery to be incapable of putting out the 12.3V it showed when doing an open circuit voltage check. Next time, I'll know to measure the voltage at the battery while an assistant turns the ignition switch, thus loading the battery.

Autozone replaced the battery for free as part of their battery warranty.

 

You could have saved yourself a lot of time by using a battery hydrometer to test the individual battery cells first.



Telcoman

 

Yes you can - IF it's not a sealed battery. Mine is.

 

Yes, you can - IF it's not a sealed battery like mine.