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merck99 06-10-2019 10:16 AM

Duvac Alternator
06 Holiday Rambler Vacationer Cummins ISB pusher. On my way from Pa to Indianapolis my alternator died. A local truck garage replaced my Duvac with a Delco. I did a voltage check and at 13.99 volts I was good to go. 20 minutes down the road Alt light and buzzer came back. I checked voltage at 14 volts, so it is charging but indicator light does not like it. No help from the mech, I now have it home so my choices seem to be putting a duvac back or doing a jury rig to make it work. Garage will refund price of part only if I send it back. Any experiences or suggestions?

CountryB 06-10-2019 11:02 AM

2 Attachment(s)
The Duvac system (is the "Battery Isolator" device, not the alternator) requires a "voltage sensing" terminal on the Alternator. The Leece Neevile alternators and the Delco 28SI has that terminal. So both alternators will do the same job.

Check the wire connected to the "I" terminal on the alternator. That terminal is what shuts off the dash light. Perhaps the wire was not reconnected during the installation or the mechanic didn't tighten it down fully.

Note: as noted in the instructions below, sometimes the coach builder uses the "R" terminal to turn of the dash charge light. So mechanic may have put the wire on the wrong terminal. But that would be the exception.

Did the light stay off at first then started to flicker or come on after driving awhile? If so, that is usually do to a loose connection.

twinboat 06-10-2019 01:32 PM

Did you happen to have the generator running ?

That sometimes confuses the Alt light system with the 2 charging systems running.

MSHappyCampers 06-10-2019 02:24 PM

Hi ! Welcome to IRV2! We're sure glad you joined the gang! :dance:

It sounds like CountryB may be on the right track! Have fun and keep her between the ditches!

Good luck, happy trails, and God bless! :thumb::D

merck99 06-10-2019 05:04 PM

Thanks for the input. First the alt light did start to flicker then stay on. the buzzer eventually stops. The alternator that was installed is a 24si. Also no loose wires and the 24si only has two terminals beside the run pos &neg. The mech put the only wire on I. I then tried switching to the R, with no change (steady alt light) I do not know if the reading is instant since I did not leave it on that terminal for more than a few minutes. I read on a thread about running an additional wire from the battery and changing the isolator, but I don't like doing it until I understand why. Thank You

CountryB 06-11-2019 05:15 AM

2 Attachment(s)
The 24SI alternator has the sensing terminal as an "option". If the one you had does not have the sensing terminal, then it is the wrong one. You should get a refund (or bite the bullet) and get the correct one. You can Not use the "R" or "I" terminal for the sensing terminal.

Top photo is the 24SI (without sensing terminal)

Bottom photo is the 28SI

merck99 06-15-2019 07:55 AM

I took the good advice from country b and put the correct leece neville alternator in. I now have the correct voltage (according to the vendor) 14v output and 7 volts signal voltage. I still have alt light and buzzer. I swapped out the relay, according to the 06 Holiday rambler owners manual. I do not have a wiring diagram but I can't imagine what else could be in that circuit.

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