Hi guys,

I own a 2004 RX8. A year ago, I had to replace engine and other related components due to water issues (car plunged into a deep pool of water during a rainy day). Since the new engine with new components, car was fine. About 6 months later, the dashboard display monitor went crazy... flickering with letters and numbers like matrix... and I found out that this was a common problem by removing the battery wire for half and hour and connect it back. Problem was solved and it did it again 3 months later. Then I did not remove the battery wire this time and just let the dashboard monitor go crazy.

Today, I noticed that the 4 lights in the radio console, the A/C and airflow mode selector (window, foot, front, and rear window) did not illuminate. And I have a Bluetooth transmitter that plugs into the cigarette power and allows me to listen to the music from my phone. The music was stopping and playing like there is a bad connection when you watch a movie online. And when I turned off the engine, the monitor display was still on, and the radio was turning on and off for like 10 minutes. After half and hour, the problem were solved.

I suspect there is some electrical wire issues. I called Mazda dealer to discuss the problem and they said it costs $145 for just diagnosing the car. I went to other mechanics but they recommended me to go to the dealer. What might the problem be? Is it because of the water incident I had a year ago? Or simply some wires are burnt? Why would the radio and dashboard display keep turning on and off when I turn off the engine?

Any feedback would be appreciated. Thanks so much.

 

I would go through the engine bay and check all ground points for rust. It is very common for cars that have seen water damage to get some oxidation or rust buildup on ground nodes

 

You have 1 or more grounding points corroded. Getting water around electrical components, including just a passive grounding point, will accelerate corrosion at that point. For example, just getting the battery posts damp will accelerate the corrosion on the battery terminals so fast that you will be able to see the increase in corrosion volume from one day to the next.

So, start with the battery. Disconnect both clamps (remove negative first, connect positive first), clean the clamps and the posts completely. Re-secure the clamps to the posts firmly, so they are seated well. If that doesn't solve it, you will need to begin disconnecting and cleaning one grounding point after another.

 

Check for corrosion on the fuse box as well...

I think most of your issues are fused on the one in the drivers kick panel that likely got wet

 

Thanks for the help guys. I will let you know what caused the problems.

 

May I ask which fuses are related to my problem?

 

Kinda having the same issue here I have a touch screen head unit and those halo demon eyes and now when I turn the key (2 clicks before turning on engine) my dash and my radio are having a hard time staying on(lights would be dime inside and out) my radio would reset 100 times idk if it has to do with the car not been started for about 3 weeks now and the battery is sucked dry? Im writing a list of things to check for to solve this but ill let you know if I find something hopefully it would resolve your problem as well.