Our old "cheap" test was to disconnect the positive battery cable while the engine was running, so it was powered by nothing but the alternator. Loading it down with lights, heater fan etc, if it kept running well meant that the alternator was putting out plenty of juice.
I am not sure how "safe" it is however to do this while the engine is running and the battery charging/venting - sparks might cause an explosion. The correct thing to do is to pull the alternator & have it tested. I am also told that if you measure across the battery without the engine running, you should get a little over twelve volts. But this assumes your battery is charged at least somewhat. Doing the same measurement with the engine running should get you fourteen to fifteen volts. But, a bad battery/bad cell would generally have an impact on both of these readings, making it imprecise to determine whether you have a bad alternator or battery. Clear as mud now? Rick Gregory '74 Triumph Spitfire FM15447UO '69 Austin Healey Sprite HAN9U81988G Great Falls, Montana http://www.spitfire.gregory.net -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] Sent: Thursday, December 05, 2002 6:46 AM To: [EMAIL PROTECTED] Subject: Alternator Test Hi all, I was advising another lister about testing his alternator, but I have forgotten how to do it, and I cant find the post that I originally got the info from, can someone put me right on how to do it please. I know I need 14.5 volts and I have a digital voltmeter. Other than that............................? Happy Spitting...................John (in the United Kingdom) Spit Mk II (1966) in bits..or as some would say (in restoration) Spit Mk III donor car ( I am nearly a collector) Mk IV chassis with all running gear.......(I AM a collector) Outgoing mail is Virus Free. Checked by AVG Anti-Virus-Guard (http://www.grisoft.com /// [EMAIL PROTECTED] mailing list /// Send admin requests to [EMAIL PROTECTED] /// or try http://www.team.net/cgi-bin/majorcool /// Archives at http://www.team.net/archive /// Send list postings to [EMAIL PROTECTED] /// Edit your replies! If they include this trailer, they will NOT be sent.
