Engine Electrical Problem

[1992GSX]

Alright, so I have searched for this answer to this for countless hours and I have not been able to find anyone with this issue. I have 3 warning lights on my dash that are lit. Coolant, brake, and battery. I know what most of you are thinking, its the alternator. I replaced the alternator about a month ago. Thinking possibly I received a faulty rebuild, I went to Auto Zone and had them check the battery and the alternator. Both of them checked out fine.

What happens is when I start the car they come on very faint and steadily glowing. If I turn my lights, same thing, just a little brighter glow. Now if I begin to drive they start to flash very rapidly. The higher my rpms go up, the SLOWER and BRIGHTER they begin to flash. The rapid blinking begins to slow at about 3k. If I am sitting in the 5-6k range they flash extremely bright and a lot slower than before. At this point I can actually see the rest of my gauge cluster blinking and even my headlights, but only if I am in that high rpm range. I have not noticed a loss in driveability, but I have noticed a loss in power when I'm WOT. Especially in that upper rpm range.

Like I said, I had the battery and alternator checked, and I even checked the 80amp alternator fuse in the fuse box under the hood and they are all fine. I also checked the gray plug going into the alternator and that is secure. What in the world could this be????? Please help!!!!

I should also add that I am throwing a CEL right now for my knock sensor. It says that it is disconnected, I got under there tonight and found that the silicone that holds that wire in place on the sensor itself has melted and the wire has fallen out. I will need to get a new one.

My mods list is up to date also.

Thank you in advance

 

[Colt4G63 also]

I wouldn't trust AZ's diagnosis if they had the last voltage tester on earth. See what kind of voltage your system is running at those various RPM ranges. I would suspect the voltage is fluctuating wildly, based on your description of the symptom. Assuming the voltage checks out, I would be looking for a short or open in your instrument cluster wiring. Usually the problem can be traced back to a fault where the plastic film on the back of the cluster is not getting a good connection to the plug that goes into the cluster. Also check for cracked traces on the film.

 

[1992GSX]

Thanks for the advice. I'm heading out of town (vegas baby) for the weekend so I will check that out as soon as I get back.

 

[1992GSX]

so I'm now electrical expert by any means, but after a lot of testing, pulling my hair out, and kicking the spare tires in my garage, I figured out that it was the internal regulator in the alternator that had gone bad.

Good thing the replacement I bought had a lifetime warranty Got a replacement, bolted it back up and good as new.

 

[Drifte]

Related issue here. But in addition my temp gauge fluctuates rapidly. I also have a new alternator and am thinking it may be a ground issue. I'm going to check it out tomorrow. Also my blower motor fluctuates too! More tomorrow too many variables at the moment.
[edit]
My lights flicker
My blower motor speed changes rapidly
Car heats up very fast, like 30seconds? Coolant system is bleed
Radiator fan doesnt turn on
Car died once or twice
Lower rpm the car stays cooler and lights dont flicker. Higher RPM things get wacky.

Other info: Car has a brand new engine, and a wire tuck but no problems until yesterday. Alternator is new and has probably 1,000 miles or so on it.

 

[Drifte]

I checked over grounds and everywhere reads 12.58v off the battery including the battery itself. the temp gauge is still iradic (maybe a bad thermostat, its new..). My lights and fans slow down and whenever they dim the temp rises quickly. My radiator fan wasnt turning on because of the rad temp sensor, right now i have it jumped so it runs all the time. Its 20 degrees outside and im having over heating problems?!!