Hi everyone, here is my problem. My car stops charging once it reaches normal operating temp. The alternator dips really low in volts.

I am positive it isnt the alternator, I've replaced it twice in the past month with brand new ones. I had an aftermarket chip in place, I removed it but the problem persisted. Yesterday, I went and bought a new ECU. Thought the problem was fixed, but it came back. What could cause this charging problem?

By the way, I cant tell if its throwing any codes. I removed the airbag (replaced steering wheel)and the "service engine soon" light was constantly on so i disconnected it at the time. Plus, I dont have an auto-xray or anyhing.

Any ideas? The battery is new as well...

This is a 92 305 TPI G92

 

what voltage does it drop to?
how long did it take for the prob to return after ECM replacment?
maybe you should temperaraly reconect the service light so you can flash the codes.it doesnt realy sound like thats the problem though it sounds like something is drawing too much current and dragging down the alt.
did you put the perf chip in the new ECM?

 

Get a voltmeter and measure the battery terminals when you think it's low. Don't forget if the electric fan is running or AC voltage WILL dip somewhat. Also the voltage regulator IC in the alt will throttle down output when it gets hot. It has a thermistor that senses temp of the IC and the heat from the rectifier pack and adjusts output accordingly. To be of more help I really need to know how low it gets.