2010 Mazda 3S Auto - Random electrical problems

:
2018 Mazda CX-5 GT
My wife had her car serviced for the sticky dashboard recall back in the Fall of 2017. I doubt this is related, but just throwing it out there. Also, last month, I had to replace two front tires since she hit a pothole and blew up the low profile tire. Good thing the wheel wasn't cracked. The car has about 38,500 miles on it.

Occasionally, her map lights will go on and the door ajar warning light will go on even though the doors are fully closed. There may be other weird lights flashing and I can't remember what else is giving false alarms. Not sure what the gremlins are so just posting in case others have experienced a similar issue.

I have already searched the Mazda 3 forum and no similar issues were found.

Thanks in advance.
 
Was the car purchased, new?
Here's what I suggest:
Tires: If potholes are numerous, you may consider down-sizing the wheels and tires by one inch. The resulting (higher profile) tires should protect the wheels and provide a softer ride, although as a tradeoff, dull the steering response a bit.
Map light: The door switch may be able to be adjusted. Did you take a close look at it? Also make sure there is nothing preventing the door from fully closing. An unused seatbelt can do this.
 
Was the car purchased, new?
Here's what I suggest:
Tires: If potholes are numerous, you may consider down-sizing the wheels and tires by one inch. The resulting (higher profile) tires should protect the wheels and provide a softer ride, although as a tradeoff, dull the steering response a bit.
Map light: The door switch may be able to be adjusted. Did you take a close look at it? Also make sure there is nothing preventing the door from fully closing. An unused seatbelt can do this.

Yes, it was purchased new. The electrical issues just started sometime this summer, before the pothole incident. I'm not sure they're related. I guess if it gets worse, then maybe I'll have it looked at. I recall the TPMS went off and it was a false alarm. The TPMS also did the same on my previous 2011 Mazda 3i. Again, false alarms since I pulled over on the interstate and my tire gauge found normal pressure. I eventually had to the TPMS on the 3i replaced - dead battery.

I did the wheel downsizing on my former 2003 Miata - the 16" wheels were really heavy so I went to 15" and it improved the handling as well as lower sprung weight. I had to get the weight weights mounted in a different location since they rubbed against the calipers.

Not going to do this on the 3S - the tires are new...and the others were replaced 2 years ago and have < 10k on them right now.
 
It seems like there is no calibrate/reset button? I believe this is what I have and after setting it when my 3 was new, I have never had a false alarm (5 + years).
 
Battery Terminal Corrosion - Cause? What are the White & Red wires for?

Broken Batt terminal.jpg

Our 2010 Mazda 3 had no power yesterday and after opening the battery compartment, I found the + cable was no longer connected to the battery terminal. I had inspected the terminal for corrosion in the spring and it was clean. Around 2018, Labor Day weekend, the car wouldn't start and I found some green powder caked up around the battery terminal connection and cleaned it off and put some petroleum jelly on the positive terminal to prevent corrosion.

NOTE: this is a replacement battery I purchased from Costco that was installed around 2015. I had the same battery installed in my previous 2011 Mazda 3i Touring; and never experienced this problem - I usually did park in the opposite direction than my wife so maybe this prevented the problem my wife's experiencing. See #1 below.

I have several questions:

1. the problem occurred after a hot summer in both cases - is it possible that parking the car facing slightly downhill caused some acid to leak out of the vent caps onto the terminal connection? Note the fluid path is such that it would accumulate on the terminal connection since the parking spot slopes from the driver's side to the passenger side (the hill slopes downhill in this direction).

2. Where does one find a replacement terminal connector? I searched multiple online Mazda parts sites and there isn't anything "Battery" related under the "Eletrical" Category.

3. Is it necessary to use the OEM part? There should be a reason why the black plastic part containing the Red and White Cables, appears to a heat sink? Why is there a White cable at all?

Thanks in advance!
 

Attachments

  • IMG_20191014_205734701.jpg
    IMG_20191014_205734701.jpg
    747 KB · Views: 241
Last edited:
1a. How often do you check the battery to ensure that each cell's water/acid level is correct? I check my battery at every oil change. Letting a cell go dry will reduce the life of the battery.
1b. Overfilling of one or more cells could cause corrosion from loose-fitting/leaking caps.
1c. A crack in the battery case could allow corrosive gas to corrode the terminals. Check for any liquid on top of the battery, near the caps. Fully charge the battery after properly filling the cells with distilled water, if needed.


2. Your local auto parts store should have generic ones. Ask if they have the same style as the OEM. If necessary, pick one up at the dealership, but the online dealership parts sales should have them. If you can't find it on their sight, give them a call.
3. I would use the OEM style if it includes an attachment point for the white wire.

By the way, under high ambient conditions, 4 years of battery life is fairly typical. Many folks in Arizona replace car batteries every 3 years.
 
There is a bank of terminal connectors and generic battery cables at any auto parts store. I would also use a torch and solder it onto the old harness. Crimping only...it'll probably corrode after some time.

If you want OEM, you will almost certainly have to get a wiring harness. That will fix it though. Better than a terminal. Dunno how costly.

-Mike
 
Yesterday, I called up a Mazda dealer and the Parts guy was able to explain that the wiring harness contained the Main Fuse in the black plastic thing and the clamp could be detached. I was able to remove it using some water pump pliers and a box wrench. It took some searching at the auto parts store; however, I found a Top mount terminal clamp that had an attachment to the OEM bracket. Everything is working again.

Hopefully, the bad connection was the cause of the electrical problems I mentioned up thread. Thanks for your help!
 
Back