right that.i had a 944 porsche and she ran terrible and would not idle and all seemd good.she had a good 14v also coming out of the alt.i was exasperated.finaly checked the ac current.yep she was 3-4v which meant one of the diodes was not functioning as it should.changed the diodes problem solved.it was screwing up the commputor.
--- On Tue, 1/4/11, Alan Lambert <[email protected]> wrote: From: Alan Lambert <[email protected]> Subject: Re: [alfa] Alternator light - sporadic behavior To: "ira kaufman" <[email protected]> Date: Tuesday, January 4, 2011, 4:26 AM Diodes are replaceable Alan Lambert --- En date de : Mar 4.1.11, ira kaufman <[email protected]> a icrit : De: ira kaufman <[email protected]> Objet: Re: [alfa] Alternator light - sporadic behavior @: "AlfaCyberSite" <[email protected]> Cc: "alfa" <[email protected]> Date: Mardi 4 janvier 2011, 6h14 why do you have to check diodes?the alt is caput period.just to enjoy the checking may be a good reason tho. --- On Mon, 1/3/11, AlfaCyberSite <[email protected]> wrote: From: AlfaCyberSite <[email protected]> Subject: [alfa] Alternator light - sporadic behavior To: "AD" <[email protected]>, [email protected] Date: Monday, January 3, 2011, 10:52 PM Stefano, if must be catching. Just recently my alt light has taken several seconds before going out. Tonight I needed to run a quick errand and alt light was still glowing a bit as I got on the freeway and it then went to a medium bright to full bright, almost as if it was on a blinker of sorts. When I eventually stopped for a light, it glowed bright red. Car did restart after short errand. Bottom line, using my multi meter I got 12.3 volts at the alt. revved the engine and it didn't move - it should read around 14.2 or better (believe that's right). Meaning the battery isn't dead yet, but the alt isn't doing anything. My alt belt is a little loose, so at least worth tightening before ordering a new one. I just dug out a tip from Jeff Greenfield to check for bad diodes: "Set a DMM (? - I used an old but reliable analog meter at the time) on a low A/C (not a typo) volt range and measure the A/C voltage at a fast idle with the system under a load, (lights, and other item's on such as A/C)." "Anything more than about 200mV (.2V) is too much." I'll try it on mine tomorrow, but not hopeful. I hope this helps you nail down your situation. In my case I'll probably also run it by the Interstate guys (front unit here) to use their more sophisticated tester. Do make sure you're not running off the battery. Biba Irwindale, CA USA -- to be removed from alfa, see http://www.digest.net/bin/digest-subs.cgi or email "unsubscribe alfa" to [email protected] -- to be removed from alfa, see http://www.digest.net/bin/digest-subs.cgi or email "unsubscribe alfa" to [email protected] -- to be removed from alfa, see http://www.digest.net/bin/digest-subs.cgi or email "unsubscribe alfa" to [email protected]
