Electrical gremlin...

:
2003 Mazda Protege 5
Hey all, here's my issue...
A little over a year ago my car would have trouble starting and the battery light would come on randomly while driving. I took the alternator out and bought a new one after having the battery tested (good). I took my old one in for the core charge and before I left the guy tested it and said there was nothing wrong with it. I said I put the new one in and now my car works so I brushed it off and left. Since then, at rondo times the battery light will come on and have various effects on the car (I assume just depends on what I'm running at the time). Headlights/dash lights will dim, wipers will slow and windows won't go up or down nearly as quickly as they usually do, radio will fritz on and off...etc. Basically, if it runs on electricity, it won't work correctly. But again, this is a random occurrence. Sometimes, the battery light will come on and turn off some time later and not effect anything at all. At the worst point, the car would lose almost complete power and bog down really bad. Recently, I've just had to jump it (starts with no issues after jumping it) and had diminished use of electrical devices. The battery is just older than the alternator and I don't think those are the issues. Is there a ground the I can check/clean or another known trouble spot? It's my daily so tearing it apart is not so much an option. Thanks in advance...(bang)
 
The alternator on our car is controlled by the ECU. If the control wire between them is broken or has a bad connection, it effectively shuts off.

Check the light green wire with a white stripe specifically for a bad connection or corrosion.

 
I would also check to make sure the battery terminals are tight and no corrosion is present. You can also follow the ground wire from the negative battery terminal to where it connects to the body, usually not far from the battery (Can't go look to tell you for sure where, my car is at the airport still). But check to make sure there's no rust/corrosion where the ground wire connects to the chassis and that the connection is tight. May not hurt to remove the bolt, clean both the terminal and the body mounting point up with some sandpaper or emory cloth and reconnect it to be sure.


This sounds like a loose connection to me. With the way i've seen these cars rust, i would suspect the ground wire. Luckily i live in the south and vehicles here stay pretty much rust free unless you live near the beach, which is almost as bad as living up north.
 
The alternator on our car is controlled by the ECU. If the control wire between them is broken or has a bad connection, it effectively shuts off.

Check the light green wire with a white stripe specifically for a bad connection or corrosion.



Doesn't hurt to check, but for it to exhibit the issues he's complaining about the voltage has to drop pretty low. The battery alone will sustain the car running without the alternator for a good bit before you start showing issues, i would really suspect high resistance, corrosion, or a loose connection somewhere. And to affect that many unrelated circuits it has to be either a main power feed into the fuse box or main ground connection... Should be relatively easy to track down for a tech decent with electrical.

has the vehicle ever been in an accident? Many times an accident can cause issues years down the road with stuff like this.
 
I had this problem also. It was the cables. Even though I did not see any corrosion, I removed the negative cable completely, cleaned it and reinstalled the same cable. It has been fine for several months now.
 
i had same problem. i removed the cables from the terminal connectors and cleaned the wire itself then put new connectors on. i paid decent money for my new ones. i hate dealing with corrosion. had no problems since then. hope you figure it out
 
This sounds like a loose connection to me. With the way i've seen these cars rust, i would suspect the ground wire. Luckily i live in the south and vehicles here stay pretty much rust free unless you live near the beach, which is almost as bad as living up north.

I bought the car from an older lady in north carolina. Unfortunately, she bought it from a Marine that bought it (or at least had it in) Hawaii. So There is a decent amount of rust.
 
Thanks for the tips though ya'll, I just have to get through my work commute tomorrow and I'll have all weekend to trouble shoot. And hopefully report back with some good news.
 
Also, there is a ground right by the fuse box...I took it off to clean and was curious what it went to so I tugged on it a little. There is a plug wires run from positive battery terminal right under the windshield...it wasn't plugged in. I can't see what it plugs in to...thoughts? I don't know how to upload pictures..
 
Also, there is a ground right by the fuse box...I took it off to clean and was curious what it went to so I tugged on it a little. There is a plug wires run from positive battery terminal right under the windshield...it wasn't plugged in. I can't see what it plugs in to...thoughts? I don't know how to upload pictures..

The 100 amp fuse probably protects the alternator, and could very likely be why it's not charging.

Download the imgur app and upload the pics from your phone. View them on the app or website, and copy/paste the links here.
 
The 100 amp fuse probably protects the alternator, and could very likely be why it's not charging.

Yea it does... I blew mine twice when I tightened the alternator belt and the wrench hit the positive terminal on the alternator.


These things can help too... The crappy battery terminal straps have cause problems for other guys.

 
this is what fixed mine. my battery would die and then the alarm would get all messed up so i thought my alarm was malfunctioning. ended up putting new terminal connectors on and cleaning the wires before connecting them. no problem since then. i also use that terminal connector spray to keep them clean now
 
I bought a new fuse and need to replace the alternator belt (squeaks), replace a split vacuum line on my cruise control, and figure out where that mystery connector plugs into. Unfortunately living in Florida the weather often times has a different idea. Hoping this storm will blow over so I can actually get things done today and enjoy the holiday tomorrow. Thanks for the tips guys! I think my terminal connectors are ok, they aren't the thin strap kind. I'm sure the cable could use some cleaning though.
 
https://imgur.com/wobcObt Here is the connector that I need to find a home for...Like I said the wires run from positive battery connection to the plug which is about in the middle of the windshield, and the ground runs to the passenger side like to the fire wall or strut mount somewhere.
 
Last edited:
ah ok when i get home ill check it out. i think that one is always unplugged though if i remember but thats just off the top of my crazy head. haha
 
https://imgur.com/wobcObt Here is the connector that I need to find a home for...Like I said the wires run from positive battery connection to the plug which is about in the middle of the windshield, and the ground runs to the passenger side like to the fire wall or strut mount somewhere.

That is an aftermarket plug for an alarm, stereo, battery tender, or something like that. Mazda didn't make it.
 
Yeah i have nothing at all like that on my 2002 or 2003.5.. Does look like an aftermarket light setup or something.
 
Replaced 100 amp fuse...no dice. Will work on cleaning more connections etc tomorrow. Suggestions for cleaning bare wire connections? Not looking to remove every crimped connector and have to replace but I'll do what I have to!
 
Back