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Topic: New alternator now the engine will not shut down - U320 1996 with a 1999 ISM (Read 905 times) previous topic - next topic

New alternator now the engine will not shut down - U320 1996 with a 1999 ISM

Puzzling - Comments Please
Tim Dianics
Pam Sapienza
Vader PupZilla Labrador Canine Beast (AKA Pup)
Columbia, MO
1996 U320 4000
2021 Jeep Gladiator, Diesel

Engine shutdown problem

Reply #1 –
Installed a new alternator. It works... Now the engine will not shutdown.....

Comments Please....😬
Tim Dianics
Pam Sapienza
Vader PupZilla Labrador Canine Beast (AKA Pup)
Columbia, MO
1996 U320 4000
2021 Jeep Gladiator, Diesel

Re: New alternator now the engine will not shut down - U320 1996 with a 1999 ISM

Reply #2 –
Ignition switch? Cut the fuel off

Re: New alternator now the engine will not shut down - U320 1996 with a 1999 ISM

Reply #3 –
Probably the wrong alternator, not DUVAC. Unhook the alternator and if everything works you know where the problem is.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: New alternator now the engine will not shut down - U320 1996 with a 1999 ISM

Reply #4 –
Yup, the ignition wire may be hooked up to the wrong terminal of the alternator.  So it is back-feeding the ignition.

It will be one of the small wires-- your wiring schematic will have the number on it.
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: New alternator now the engine will not shut down - U320 1996 with a 1999 ISM

Reply #5 –
Our thoughts too, we swapped the wires, then it would not charge
Tim Dianics
Pam Sapienza
Vader PupZilla Labrador Canine Beast (AKA Pup)
Columbia, MO
1996 U320 4000
2021 Jeep Gladiator, Diesel

Re: New alternator now the engine will not shut down - U320 1996 with a 1999 ISM

Reply #6 –
First, verify that you do have the proper DUVAC alternator.

Then make sure it is wired correctly.  Often, the small signal wire from chassis battery side of the battery isolator to alternator sense terminal is broken or not hooked up properly.
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: New alternator now the engine will not shut down - U320 1996 with a 1999 ISM

Reply #7 –
Would also help if we knew which motorhome you are working on.
1994 U280, Build 4490
Deming, NM.

Re: New alternator now the engine will not shut down - U320 1996 with a 1999 ISM

Reply #8 –
Title is: U320 1996 with a 1999 ISM

But agree,  it WOULD be better if he completes his coach identification in his signature.
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: New alternator now the engine will not shut down - U320 1996 with a 1999 ISM

Reply #9 –
TGordon,

Incorrectly wired alternators are a common problem.  If there is any question in your mind about the term "DUVAC" then the thread linked below might be helpful.  If you are totally conversant with the concept, then ignore my input.

What is DUVAC?
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: New alternator now the engine will not shut down - U320 1996 with a 1999 ISM

Reply #10 –
Quote from: wolfe10 –
Title is: U320 1996 with a 1999 ISM

But agree,  it WOULD be better if he completes his coach identification in his signature.

oops.
1994 U280, Build 4490
Deming, NM.
 

Re: New alternator now the engine will not shut down - U320 1996 with a 1999 ISM

Reply #11 –
Give a little history of the new alternator,is it the exact same replacement,is it a upgrade,did you install or a shop?What was the problem with the old one?
96 U270 BUILD 4810
85 380SL
Drummonds TN.