Mazda3 Forums banner
1 - 3 of 3 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter · #1 ·
I have a 2007 Mazda 3. Several months ago, my speakers started popping. So I turned the radio off, and they still would make loud popping sounds. Eventually the popping stopped, but no sound would come out of them at all, not even from the radio. The head unit worked, and all the channels worked, but no sound. I also noticed the beep sound that would happen when buttons get pushed, also disappeared. So fast forward a couple months- all was well, just my sound system went out. After internet research, I thought the problem may have been a blown amplifier. I have the premium sound system, Bose with 4 speakers, a sub, and the amplifier, all factory installed, and stock. So I wanted to try fixing my radio. I drove long hours for work, and I couldn’t stand not having my system. So I took out the head unit and removed the plugs. At the time, going in with confidence, I thought I would hardwire in a new radio, seeing how any adapter I could find for this specific head unit was discontinued. So I cut off the harness for the head unit to wire in a new one. This was the moment I realized I was way in over my head. So I taped off the leads, and left it. This is where things get weird, and very “coincidental”. A couple days after that my key fob stopped working. A couple days later the right side windows stopped rolling up or down. That’s when I thought that maybe some of those wires in the harness were for more than just the radio. Then the key fob started working again, and the right windows would work on and off. Things kept getting worse, the dome lights stopped working, checked the fuse, and it was blown, which I never had a problem with them before. So I replaced that, and thought I better fix what I cut off so my car will get back to normal. So I connected all the wires back to the harness (it wasn’t pretty), and plugged the radio back in, and nothing happened. The display didn’t show up either which has a different plug. So the ROOM fuse blew again, and I replaced it, and took off the terribly reattached harness again to remove the risk of a short. Then I say okay, I can deal with these problems for a bit, then a couple days later at work, my car wouldn’t start. The battery was dead, barely charged enough to bring up the dash lights. Mind you, no lights were on on the dash either. So I jump started the car, and it ran perfect, and drove home no problem. Then the next day it was dead again. And I kept jump starting it to drive it to get to work and back. While at work, it did start a couple times on its own, but even a couple hours later it wouldn’t start again. An audio guy I took It to said that he wouldn’t do an install and fix the harness because there was a huge drain on the battery when he turned the key to ignition. I’m just in a big mess over my head with this car. So finally, just a couple weeks ago, I jump started the car and it ran. When I went to back out of the driveway, the check engine light came on. Finally! I thought, finally there is a “tangible” problem. Then about 10 seconds later, the ABS light, and traction control light came on. The power steering went out. My AT light turned on, and the car started jerking. I have a new TCM in (2 y/o?) Every light in the cluster came on, and the car died. Now it will start with a jump, but it won’t run more that 2 minutes. The lights seem to go away if I press on the gas, but when I let off, the lights come back, and the car dies. My mechanic father-in-law says it could be the ECU or BCM. My interned research says a bad ground or bad alternator. I lean more toward the ground issue since the audio guy who’s been doing it 25 years says there’s a drain. It’s just so coincidental that when I cut that harness, everything went to brimstone in 2 weeks. Any suggestions please!!!
 

·
Registered
Joined
·
3 Posts
As I was reading this I honestly looked around to see if someone was watching me and laughing. I know what you're going thru since I did almost exactly the same thing last year. I have spent the majority of the time since going thru nearly everything electrical on the car. I've managed to get it to a point I can be proud of finally. At least you were smart enough to save the harness plug lol I thought I knew enough to wing it. Turns out,I knew nothing!
Did you cut all 3 plugs from the harness or just the big one? One of those smaller plugs was where I had most of my problems originate. Whether it was the lack of being plugged in or some other result of my ill advised machinations I'll never know.
 

·
Registered
Joined
·
1,081 Posts
A weak battery will cause all kinds of crazy electrical issues in our cars. That would have been the very first place I started.

As far as repairing your hacked wiring harness, it needs to be soldered back together, and sealed with marine grade heat shrink. CAREFULLY. In your haste, it is very possible you switched two wires. I'm not saying this happened, but a black wire with a green stripe looks an awful lot like a black wire with a blue stripe. Just saying.
 
1 - 3 of 3 Posts
Top