UPDATE: Nevermind guys, found the problem
Torn harmonic balancer on the crank pulley. Car is C5 2001 2.2hdi.
For years I've had intermittent loss of alternator voltage for between 1 and 3 seconds, once every 3 months or so.
Never thought anything of it.
Recently had the following happen:
- Started the car - easy start, all good. Proceeded to drive out - lost power steering and got ABS/ESP fault.
- Shut engine off, waited 10 seconds. Started again - easy start, power steering works, no fault on screen or dash.
- 100 meters down the road I noticed voltage reading 12.2 instead of normal charging voltage. Few seconds later lost power steering again.
- I pulled over expecting something wrong with the belt. Belt relatively new, 6 months old, not torn, spins normal, but very hot to touch.
- Assumed AC compressor is stuck and belt is rubbing at it. Started engine, turned off AC - everything normal.
- Another 100 meters down the road voltage dropped to 12V again. Belt was smoking. Drove home - no charging voltage, but power steering works - and left the car overnight.
- Next day no matter how many times I start - no charging from alternator, and it gets very hot, belt is smoking, but no slipping visible on any pulley even with slow-mo camera.
- Found regulator cable a bit torn - fixed it - still no charging.
- With main lead disconnected and regulator disconnected, alternator gives off 0.5V.
- Removed belt - all pulleys rotate easily and alternator rotor is visibly rotating too.
- Removed alternator, removed rectifier and regulator - regulator brushes visibly worn off, but not to the point of no contact.
- Replaced rectifier and regulator with new quality aftermarket parts, put alternator back in car - still no charging voltage.
I need some common reasons that may cause no charging from alternator, before i bite the bullet and buy a new alternator, as they are getting pretty expensive.
Most importantly - when the regulator cable is disconnected and the engine is running, I get battery voltage on the regulator cable - is this normal? What should the voltage there be?
Also what voltage is the alternator expected to give off with regulator cable disconnected?
Can I spin it with a power tool and measure something off the terminal in order to test it?
Thank you!