Bad Relay?
 

I just replaced my Alternator this weekend and put new belts on due to it not charging my battery (had the alternator tested and it came up with a bad diode)

After I started the car up after placing everything back where it goes, I was getting an electrical kind of sound (like a buzzing or vibrating kind of sound) coming from underneath the dash. The dash warning lights for everything were also flickering when the buzzing sound was present. Whenever I raised the RPMs by stepping on the gas, the buzzing would stop along with the warning lights briefly. I thought it was maybe the ECU or the Relay next to it... About 20 minutes after I discovered the noise, the engine dropped from 2k to 1k RPMs quite suddenly, then slowly dropped from 1k to stalling over ~4 minutes...

Since I can't get the car to start again, I cannot locate where the sound was coming from...

Does anyone have any ideas? I'm hoping for a simple/cheap fix.

If there is anyone you might know of who specializes in RX-7s in the area that come take a look, that would be great as well, I'm baffled. Every time I fix something wrong with my RX, something else comes up.

I'm in Pensacola FL.

Usually when all the warning lights are on is because the alternator isn't working at all like it doesn't have a belt going to it.

IF the car is a series four car, then it's the alternator relay inside the CPU that is buzzing. Your new alternators regulator is bad. The alternator relay in the CPU that is buzzing, is NOT bad.

The alternator relay is a passinve item. the positive side of the alt relay coil has batt voltage anytime the key is to ON or better. The altenator relay coils negative side only has a gnd on it when the alternator is not turning or if the guts of the alternator go bad.

For some unknown reason, your new alternator is rapidly putting a gnd on the alternator relay when the alternator is turning, then removing the ground. It's some defect in the new alternators regulator and or internal wiring.

Try another ALTERNATOR.

Your series four alterntor has two wires on its small plug. One BLACK/WHITE and the other WHITE/BLACK. If you depin the White/Black wire, the buzzing of the alt relay will stop. If you remove the White/Black the alternator will not *put out* when the engine is initially started, but will require the engine to be rev'd quickly to over a couple grand , then it will self excite and put out and put out for the rest of THAT drive cycle. You don't wanna do that though. The Warning Lights won't work right (all lights on when engine off and or alt not putting out). You want another alternator.

I know about this problem because.....................having nothing else to do, I installed new regulators/brushes in several spare alternators I own. One alternator was series four. I installed each alternator temp in a car and took 'em for a spin. One alternator caused the buzzing alt relay symptom in the CPU. Removed that alternator and installed another series four and the problem went south. Someday I'll replace the bad regulator I had installed ithe BUZZER ALT. Someday, not today or tomorrow. Regulators/brushes are cheap. About 26bucks on E Bay. About fifty bucks at AutoZone,.