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Steve Tinker · 12-07-2010, 12:38 AM

PB - the alternator voltage does seem a low @ 13.1 v. What does the voltage go up to when you increase the engine revs?
When I installed my underspeed pulley (which actually runs the alternator at a lower speed) I was getting 14.1 v @ 750rpm and 14.5 v @ 1250 rpm.
Your initial low voltage could be a faulty alternator, or a high resistance ground.
To really know the answer to a faulty alternator you need to load test it - most auto-electrical places (preferably Bosch agents) will be able to do this.

12-07-2010, 12:38 AM	#6
Steve Tinker Registered User Join Date: Dec 2008 Location: Queensland, Australia Posts: 1,522	PB - the alternator voltage does seem a low @ 13.1 v. What does the voltage go up to when you increase the engine revs? When I installed my underspeed pulley (which actually runs the alternator at a lower speed) I was getting 14.1 v @ 750rpm and 14.5 v @ 1250 rpm. Your initial low voltage could be a faulty alternator, or a high resistance ground. To really know the answer to a faulty alternator you need to load test it - most auto-electrical places (preferably Bosch agents) will be able to do this. __________________ 2001 Boxster S (triple black). Sleeping easier with LN Engineering/Flat 6 IMS upgrade, low temp thermostat & underspeed pulley. 2001 MV Agusta F4.