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Topic: Altermator Not charging . (Read 671 times) previous topic - next topic

Altermator Not charging .

Last year the alt stopped charging, If I gave it a couple good whacks it would it would kick in and charge at about 14v . I took it off to have checked out, was told the brushes where sticking , the guy did what every at no charge . again not long before same not charging started, at that I ordered a rebuilt alt, with new alt in place, its not charging at all !!!  :-X Help Please  :o   
1992 U300 Anniversary Edition wrong color DDC6v92T Big step up from my 1983 35' fc Blue Bird .

Re: Not charging .

Reply #1 –
What model alternator was originally installed, and what model was it replaced with?
Peter and Tammy Fleming
1991 U300 GV 40 - Sold, owned for 4 years
Downsized to Roadtrek Popular 210 class B

Re: Not charging .

Reply #2 –
Have the regulator checked out, it could be bad. Are you sure the current alternator is wired the same way as the original? I believe there are some diagrams on this forum somewhere. Maybe a member can point you in the right direction.
'The strength of the effort is the measure of the result'
1995 U320SE
40'
#4740
#17648

Re: Not charging .

Reply #3 –
A big reason that I like to have a local shop rebuild the old alternator. Did you do the replacement? Do you need a photo of the wiring? Check to make sure no wires were broken in the R&R.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Altermator Not charging .

Reply #4 –
This alt, looks the same as the one I took off . it wasn't the original' it did however wired up the same . The output at the alt is 14 amp, the gauge however is wherever the Battery  . As I'm driving the coach, I can see the voltage dropping at the gauge . I have a battery charger onboard, to keep the battery up, so I fire up the generator .  that's about it . thanks guy for all help  :o         
1992 U300 Anniversary Edition wrong color DDC6v92T Big step up from my 1983 35' fc Blue Bird .

Re: Altermator Not charging .

Reply #5 –
Quote from: lovetogo –
This alt, looks the same as the one I took off . it wasn't the original' it did however wired up the same . The output at the alt is 14 amp, the gauge however is wherever the Battery  . As I'm driving the coach, I can see the voltage dropping at the gauge . I have a battery charger onboard, to keep the battery up, so I fire up the generator .  that's about it . thanks guy for all help  :o         

14 amps or 14 VOLTS?
And, when you say voltage drops as you drive, how low does it get?
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Altermator Not charging .

Reply #6 –
What is the voltage at the batteries when the voltage at the alt. is 14? Maybe you have a bad isolator.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: Altermator Not charging .

Reply #7 –
Why don't you pull the alternator off and have it tested? This will save days of guessing. Re-built alternators, water pumps, etc have a poor reputation with assembly line work done by minimum wage workers with only basic training. Bead blasting with a little added paint does not mean it's a quality rebuild. Electrical shops have excellent reputations and will stand behind their work. The U300 alternator on the Detroit is in a very easy location for quick R&R.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Altermator Not charging .

Reply #8 –
The replacement alternator needs to be modified for DUVAC system.
1994 U280, Build 4490
Deming, NM.

Re: Altermator Not charging .

Reply #9 –
Quote from: red tractor –
What is the voltage at the batteries when the voltage at the alt. is 14? Maybe you have a bad isolator.
Firing her up today , for trip tomorrow, got it, amp not volt . Will check volt @ batt , today . thanks for all help guys  ;)
1992 U300 Anniversary Edition wrong color DDC6v92T Big step up from my 1983 35' fc Blue Bird .