SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: challenger on December 22, 2010, 06:35:11 PM

Title: alternator
Post by: challenger on December 22, 2010, 06:35:11 PM
my 2nd  battery keeps draining. the alternator is only pushing 13 .5 volts at the first battery and  2nd 13.1 is that norm  or does that seem low its a 08 F350  6.4
thanks for your help
Ken
Title: Re: alternator
Post by: crewchief22 on December 22, 2010, 06:40:19 PM
That is low.  You should be seeing 14.1-14.5 range
Title: Re: alternator
Post by: challenger on December 22, 2010, 06:46:49 PM
Dam that sucks... so the alternator is bad   ok upon more checking it goes to 14.5 after 1 or 2 min so i shut it down and again after 2 min it goes to 14 v is this norm
Title: Re: alternator
Post by: KonaGuy on December 22, 2010, 08:38:01 PM
this is normal, u have to give the glow plugs a minute to stop drawing power. every ford diesel has done that for as  long as i have been working on them. I ve been doing it a while. ;D
Title: Re: Re: alternator
Post by: Nordie on December 22, 2010, 09:05:38 PM
My dmax is the same as well...upon cold startup i only charge like ten volts...after 10 seconds it jumps up to 14.5 been the same since day one...i would say one batt is done...but pony up and buy two...i always buy two batts...that is one thing that has always grinded my gears about ford and dodge you get very vauge gauges....
Title: Re: alternator
Post by: challenger on December 22, 2010, 09:47:05 PM
Thanks
just going to go get them. dam right at x mas  :banghead: this sucks you know i have no problems at all when i have  extra but when its tight everything goes to shit WTF
Title: Re: alternator
Post by: Hddaddy on December 23, 2010, 09:47:24 AM
Hey if your looking for batteries come by my shop in Ontario. Will get you a good deal on some USA made batteries. We are a dist. for Deka batteries, manufactured by East Penn. PM if your interested.
Title: Re: alternator
Post by: challenger on December 24, 2010, 09:42:01 AM
 Thanks
Title: Re: alternator
Post by: Ralph Brunt on December 24, 2010, 06:06:29 PM
before i would spend all that money on batts i would perform a parasitic draw test.
Title: Re: alternator
Post by: challenger on December 24, 2010, 06:56:00 PM
before i would spend all that money on batts i would perform a parasitic draw test.
is that just a load test
Title: Re: alternator
Post by: Ralph Brunt on December 24, 2010, 07:36:49 PM
is that just a load test

remove neg batt term and hook your dvom in line from neg post to neg cable. set meter on amp's first and if it is under 400 or so mili amps then set meter to mili amps. you should have no more than 100 mili amp draw. if you do start pulling fuses one at a time until the meter goes under 100 mili amps. when it does you have found the curcuit causing the draw and killing your batteries.

no its not a load test it is a draw test on your vehicles electrical sys.

no draw = bad batt
Title: Re: alternator
Post by: GT Jets on December 25, 2010, 10:35:28 AM
remove neg batt term and hook your dvom in line from neg post to neg cable. set meter on amp's first and if it is under 400 or so mili amps then set meter to mili amps. you should have no more than 100 mili amp draw. if you do start pulling fuses one at a time until the meter goes under 100 mili amps. when it does you have found the curcuit causing the draw and killing your batteries.

no its not a load test it is a draw test on your vehicles electrical sys.

no draw = bad batt


Another way to do this is to use a test light in series between the battery lead (I like to use the negative) and the battery post, the light will glow if there is a substantial draw. Have you checked to see if the charging is going to both batteries? in other words, did you use a voltmeter on the battery itself while the engine is running, could be a bad connection or a blown fuse to one or the other battery, only charging one, but drawing on both...... ;)

GT
Title: Re: alternator
Post by: challenger on December 25, 2010, 10:47:56 AM
thanks for all the responses. i will give them a try  before buying  new battery's   
SMFPacks CMS 1.0.3 © 2026