I need help! I just got my FC on the road and some very strange things are happening. On Sunday I replaced the battery in the car and now the radio doesn’t work. When I turn it on the door light in the center display comes on and it looks like the radio gets juice for a split second. Then I noticed that the dome light quit. Just got back from lunch and on the way to the deli I looked at the gas gage, ¾. Sandwich in hand got back in the car and drove off, looked at the gage again ¼ and dropping. Then it started to go up. Got to ½ and then went down again. What the hell is going on? I have heard of these cars having electrical woes but all this crap worked on Friday! Things I did to the car since Fri.
Cat back exhaust
Drain and refill coolant
New AFM
Oil change
Reroute plug wires
New Battery
Shifter bushings
Belts
Please HELP

 

You will need to learn to debug electircal systems. For this you will need a Volt-ohm meter (VOM), also called a multi-meter. A nice basic one is about $30. A test light is also handy. You will also need a wiring diagram for your car, which is in the factory manual (for later years).

One basic problem is that the electrical connections, including grounds, get corroded and don't conduct well
anymore. Get some contact cleaner and wire brushes and hose down your electrical connections. Mazdas in general are not very good in this department, especially with age.

You can farm this work out, but it is expensive, and it will be recuring once the car is old enough.

 

Good luck, do what he said above, and be prepared to spend WEEKS looking for the culprit, as well as using every 4 letter word you know, as well as making up a few of your own. I am currently dealing with a electrical gremlin in my bad boy, and it hasn't run for 4 days now!