Why do you need an ECU? Just asking because there have been several instances where a shop says that's the issue and it's not. ECUs rarely have issues.
Why do you need an ECU? Just asking because there have been several instances where a shop says that's the issue and it's not. ECUs rarely have issues.
Well im at the end of a long battle with my charging system. In the morning when i start the car if left to idle theres sometimes 30 or so seconds untill the car starts charging. While driving, a demand on the system makes the volts drop to under 13. After a second or so it will jump back to 14. At night with the lights on, just rolling up a window makes the volts drop. The cooling fan kicking on will cause the car to shudder as the volts drop and it tries to recover charging. With all the trouble ive had under charging its over charged past 16 only five times i know of..
The fun part.. I have checked the amp draw on the cooling fan. It checks out ok. I have had four alternators. The last, and my current, is strait from mazda. I have checked the signal wires per the mp5 manual and everything is in spec. Found a second test that involved a lab scope. That too checked out. Checked signal wires for short to ground. I even bypassed the cars wires and ran my own wires from the ECU to the alt. Still nothing.
Soooo.. I have two things left to do.. Find and check all the grounds for the ECU. If thats good im going to buy a new ECU
