Author Topic: Low Voltage  (Read 5017 times)

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Offline Bwilson

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Low Voltage
« on: April 02, 2014, 01:07:06 PM »
When I went to get my 2006 Discovery - Cat C7 ready for a trip a buzzer was going off and it sounded like air was escaping under the dash when I entered the coach. The starting battery voltage was low, it was almost dead and I had to jump it to get it started. Could this low voltage cause the buzzers to go off and the gauges go crazy? After I got it started I took it in for repair and the batteries were charged and they couldn't get it to duplicate the problem. What do you think could this just be a low battery problem? 

Offline ziggyh

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Re: Low Voltage
« Reply #1 on: April 02, 2014, 02:36:12 PM »
Low voltage is a problem with vehicle electronics and can cause erratic operation of gauges ect. Perhaps you heard the low air pressure warning buzzer because of the incorrect system voltage.   If you pump down your brakes around 60 psi you could see if that was the buzzer you heard.

ZiggyH

2007 Revolution LE
C9

Offline Brett Wolfe

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Re: Low Voltage
« Reply #2 on: April 02, 2014, 02:45:33 PM »
Indeed low voltage can cause all kinds of issues with modern vehicles.

But the air leak in front may be a different issue-- what is air-driven in that area:

step cover?
horn if on driver's side?
parking/emergency brake?

If you hear air escaping again, try to pinpoint the source.

Brett

Offline Tom Bernardi

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Re: Low Voltage
« Reply #3 on: April 02, 2014, 03:07:44 PM »
Agree with the previous two posters on the low voltage.

On the noise under the dash, sometimes I turn off the heater switch after I have turned off the ignition.  When I go to start the coach the next time, the vents will shut fully and it does sound to me like air rushing out from under the dash.  This should only happen once, unless you don't turn off the heater the next time before turning off the ignition.

Tom
Tom
2017 Newmar Dutch Star 4054 / Freightliner 450HP Cummins ISL / Blue Ox Avail / '17 Jeep Wrangler Sahara / Brake Buddy /
Silverleaf VMSpc w/Pressure Pro TPMS

Offline Brett Wolfe

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Re: Low Voltage
« Reply #4 on: April 02, 2014, 03:16:49 PM »
Tom,

Sounds like you are describing the vacuum doors for the dash HVAC system.  Most diesel pushers have a separate electric vacuum pump up front to "power" this system. 

Unlikely, but I guess one could have a compressed air powered vacuum pump-- they are made, but generally more expensive than the small electric ones.

Offline Bwilson

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Re: Low Voltage
« Reply #5 on: April 02, 2014, 05:06:42 PM »
Yes it did sound like the low air pressure buzzer. The key was not in the ignition and the buzzer would sound then go off, then the air release sound. This would go on till the battery went dead. I found this as soon as I opened the door. I have hope the it was caused by the low voltage in the battery.

Offline Tom Bernardi

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Re: Low Voltage
« Reply #6 on: April 02, 2014, 05:36:07 PM »
Each coach is different, but without the key in the ignition and turned to on, my coach's low air pressure warnings are silent.

Tom
Tom
2017 Newmar Dutch Star 4054 / Freightliner 450HP Cummins ISL / Blue Ox Avail / '17 Jeep Wrangler Sahara / Brake Buddy /
Silverleaf VMSpc w/Pressure Pro TPMS

Offline antiqueclockservice

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Re: Low Voltage
« Reply #7 on: April 03, 2014, 12:20:30 PM »
Hi, In my coach, if I get into a low voltage situation, the CO alarm will sound....

best,
Phil
Best,
Phil

Offline Bwilson

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Re: Low Voltage
« Reply #8 on: April 03, 2014, 02:28:36 PM »
The repair shop can't duplicate the problem or find anything wrong but the batteries were low. I guess I just learned an expensive lesson.