Been trying to troubleshoot no start issue with my 09 MDX. One day just wouldn't start and made clicking noises as if they battery was dead. Tried to jump start it but same clicking noises under the dash. replaced battery and the car started and worked fine for one day and then started doing the clicking sound again and no crank.
Battery was new tested ok but still got it replaced but same result with a brand new battery. Thought the starter must have gone bad so I just changed the starter today but i am getting the same clicking noises from under the dash and no crank.
I finally found the 2 starter relays and removed them. I have ordered the relays and hopefully it starts but wanted to ask if this has happened to anyone and what the issue was. I have checked the battery cables and terminals and they are good. If the relays don't fix this i really don't know what to look at next. Any hep would be greatly appreciated.
Thanks!!!

 

Recommendation as follows once the relays are back in:

1) Need a good battery. Seems like it's new, so should be OK

2) The new starter is brand new or remanufactured? Was it tested prior to install? I've bought remanufactured parts before that did not work and ended up returning for brand new. Also, double check you are getting 12v to the starter from the battery.

3) Once you confirm battery and starter are good, conduct a parasitic draw test. I've confirmed the HFL unit killed our MDX. Once disconnected, I stopped having the drain on the battery.

4) Verify your battery terminals are not corroded and the connections are firm. Also, verify your grounds are connected to the chassis and not corroded.

5) Jump start the car to see if it starts. Once it's running, test and verify your alternator is properly charging the battery (should read 14v). Again, I've had a reman alternator and it was a NO GO. Ended up taking it out and replacing with OEM.

Hope this helps

 

Thanks will try. So far jumping the car has not worked which also points at bad relays. Should get the relays tomorrow to try starting again.

 

Thank you for your suggestions. It turned out to be bad starter relays. They were a pain to get to but once i replaced them the car started right up.

 

Woa! Way to go fixing it Bruh. Skillz to pay the Billz!! Are you an electrical engineer or a sparky?

 

Far from it brother. I am in IT but I like wrenching on cars.

 

I just went through troubleshooting a parasitic power draw that was killing the battery when the 2013 MDX sat overnight. The problem ended up being the motorized tailgate close button (Part number: 35800-SED-003) located on the underside of the tailgate. $20 part
FYI regarding troubleshooting. First, I tried unplugging the Bluetooth handsfree module, battery still went dead overnight. Second, I replaced the AC clutch relay, battery still went dead overnight. Thirdly, I started unplugging fuses overnight and checking to see if the vehicle started in the morning. I found that when I unplugged the interior lights fuse the battery did not go dead overnight. I then noticed that the tailgate close button remained illuminated for what seemed to be too long. I unplugged the switch and left all the fuses plugged in and the battery did not go dead YAY!!!! New switch arrived yesterday, installed it and everything is functioning properly.