EDIT: Thanks for the input - I discovered that the positive battery cable was corroded more than I thought and was dropping voltage to the starter - there was enough to engage the bendix but not enough to crank the engine. Put together a new positive cable and cable to the fuse block, and it started right up! (I can't claim credit, I submitted my issue to Just Answer and paid $25 for someone to diagnose it for me - worked like a champ).


New to the forum, not sure if I should be posting here or in the General Tech forum but I'll start here and welcome any advice to best get input on my problem.


I have a 2007 CX9 with 210,000 miles on it and it has been the most trouble-free vehicle I've ever owned. It's never been in the shop, which blows my mind. I had the first event where it would not start recently, and I chased it down to a corroded positive terminal connection to the battery. Got a new battery, replaced the terminal connector (chasing down the cable until I got to the end of the corrosion) and it started right up.


A few weeks later, I tried to start it and it just gave a loud, single click. Pulled and checked the battery connections, put my charger on it and found it was a bit low (75%), charged it back up and it started fine.


A couple of days ago I tried to start it and again got the single loud click. Put the charger on it, and again it was a bit low (maybe 80%), charged it back up to 100%, it was putting out 12.6 v, but still just got the single click. I'm not a mechanic but I've been working on my own cars for 40 years and have become pretty decent at diagnosing mechanical issues with research, but not so good at electrical. Here's what I've tried so far:


1. Diddled with the shifter to make sure it was engaging in park. As far as I can tell it is, if it's out of park it won't do anything.


2. Checked to make sure the anti-theft symbol is not flashing on the instrument panel.


3. Tried a spare key, same result.


4. Checked the battery and cable connections, all seems to be in good order.


5. Since it seemed most obvious that I had a starter problem, I went ahead and replaced the starter, but this made no difference - still get the single loud click when I turn the key to the start position. There did not seem to be any evidence of abnormal wear on the starter teeth, which might indicate an engagement problem.


6. Pulled the rt front tire and shroud and rotated the engine by hand from the crank, it seemed to turn normally.


Not quite sure where to go next...anybody have any ideas?

 

One loud click generally means that power is getting to the starter solenoid. ( a big magnet that pulls the gear into the flywheel and activates the actual starter to turn) Since you hear the solenoid working i would assume there is a poor connection, probably the ground for the starter. You can use battery booster cables to ground the body of the starter directly to the negative side of the battery to test it. If you live in the rust belt it is possible that even though the starter is bolted to the engine and therefore should be grounded it may not be grounding as well as it needs to be. Check your engine to battery ground also. DC current requires both positive and negative have good connections. Especially the starter which draws more amperage than any other component on the vehicle.

 

i worked at a parts store for a few years, and sold a LOT of batteries. like any other part, just because it is new does not mean it is perfect. new batteries do get replaced under warranty. try a jump, if it starts, and you want to chance it, drive it to most any parts store, and they can do a load test. if not, take the battery out, and take it to a parts store for a load test. also check your alternator.