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Phantom load sources?

I am trying to track down and eliminate known phantom loads because we dry camp almost exclusively.  We have a 1998 U-320.

What are some of the common phantom loads on these units?

One on our unit is the newer stereo head unit the previous owner installed.  It is tied to the coach batteries but goes into "Stand-by" mode rather than a full off.  I need to install a physical toggle switch to turn it off.

Thank you for your help.

Chris

Re: Phantom load sources?

Reply #1 –
Are you only referring to DC loads? If you have an inverter and televisions, satellite, or any other A/C appliance, they all draw even when turned off. Examples micro-wave, coffee maker, vcr.
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: Phantom load sources?

Reply #2 –
Absorption refrigerator
Propane detector
CO detector
Propane solenoid
Engine and transmission ECU/ECM
Radio memory
Leveling system: brain and pump

I am sure I am leaving out something.

Best answer:  put an ammeter on each battery cable and start pulling fuses.
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: Phantom load sources?

Reply #3 –
Thank you.

Yes, DC phantom loads.  Our last coach had a few surprises that we didn't know about at first - like a solenoid on the main LP tank instead of a manual shutoff valve.  That solenoid drew 1 amp per hour, every hour, while dry camping.

AC loads will only be a draw when the inverter is turned on.  Normally we keep the inverter turned off.

Pulling DC fuses - are these located under the front panel to the right of the stairs as you walk in?

Leveling system: didn't think about that one, but it's needed.

Fridge:  Yup, LP fridge but it still has a draw.  This two door fridge is huge.

Thanks,
Chris

Re: Phantom load sources?

Reply #4 –
As Brett said, unless you put disconnects on both battery banks, you will have parasitic loads.
I tracked all of mine down I could, and still have about 30 watts on house batteries. ecm memory on start batteries is about 10 watts.
I cut the wire on the propane solenoid as it was a good load.
Jim C.
coachfree, previous 1997, 1999, 2000, and 2003 Foretravels.

Re: Phantom load sources?

Reply #5 –
Jim,

Thanks for the info about seeing 30 watts.  2.5 amps...  Does any of that come from your solar charge controller?

Chris

Re: Phantom load sources?

Reply #6 –
The parasitic load is very small, even with the propane solenoid running all the time. Just as an experiment watch your voltmeter drop when you turn on even a few interior lights. Even turning on a few LED interior lights will drop the coach battery a tenth of a volt in my coach. If I leave everything turned off I can be out hiking or riding my motorcycle all day long and come back to the exact same voltage I had when I left, even with the propane solenoid on all the time. I used my inverter a lot for the past couple of weeks to run my ice machine and it's murder on the coach battery. I had to run the genset after the inverter was on for only about three hours to avoid battery damage. I had to wake up in the middle of the night at least once or twice to start the genset. It was good in that it helped me keep my electric usage in perspective. Previously my largest electric consumer was my laptop computer running from a 12 volt DC power supply. I'm glad I have my propane refrigerator working again. :)
Scott Cook
1991 U300 36' 6V92TA
Old Town Penobscot 16
1984 Honda VF1100C (V65 Magna)

Re: Phantom load sources?

Reply #7 –
Quote from: Numbers –
Jim,

Thanks for the info about seeing 30 watts.  2.5 amps...  Does any of that come from your solar charge controller?

Chris
No, charge controller only charges batteries if sun, shuts off completely with no sun. Basicly what Brett mentioned with the propane shut off coil the biggest.
I disconnected inverter, as it draws current even at idle with no load.
Jim C.
coachfree, previous 1997, 1999, 2000, and 2003 Foretravels.

Re: Phantom load sources?

Reply #8 –
These coaches are HOGS when it comes to parasite loads! One of the projects in my future is tracking them down. The LP valve on my last Sprinter B would draw ~ 20 AH over a 24hr period, that's not small, but, if you use propane, how do you "cut the wire"? All I've seen are NC valves.
Dave W. (AKA Toyman )
'03, 270, 36', Build 6095, Pulling whatever I hook it to.

"Don't cry because it's over. Smile because it happened."
Dr Seuss

Re: Phantom load sources?

Reply #9 –
Quote from: toyman –
These coaches are HOGS when it comes to parasite loads! One of the projects in my future is tracking them down. The LP valve on my last Sprinter B would draw ~ 20 AH over a 24hr period, that's not small, but, if you use propane, how do you "cut the wire"? All I've seen are NC valves.
Actually, you unscrew, or unbolt the top of the solenoid valve, remove the internals and put back together. I cut the wires to the coil and taped off, and reinstalled the coil on the valve
Jim C.
coachfree, previous 1997, 1999, 2000, and 2003 Foretravels.

Re: Phantom load sources?

Reply #10 –
I went a couple of years both with and without the LP gas solenoid and I can't see any difference in battery life. I have only one 8D battery for the coach and it easily lasts more than 24 hours between generator runs. The only variable is how much I use my laptop with the 12 volt DC power supply. The cell phone I have won't charge any other way due to some weirdness. Once that phone dies and I replace it I won't have to charge my phone through my laptop anymore and I may go two days between generator runs... Put a voltmeter on your coach battery and you'll see what I mean. The voltage will stay the same all day long even with the LP gas solenoid running.
Scott Cook
1991 U300 36' 6V92TA
Old Town Penobscot 16
1984 Honda VF1100C (V65 Magna)

Re: Phantom load sources?

Reply #11 –
Idle mode draw no load on our old freedom 25 is .12 amps of 12 volt.

"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Phantom load sources?

Reply #12 –
Most inverters, turned off (i.e. not providing AC power) are still drawing 12 volt power unless you disconnect 12 volt supply. I installed a manual heavy duty battery disconnect switch on mine. Older inverters draw more 12 volt watts than newer inverters (when turned off). Because my new (6 years old) inverter draws very little power compared to my old inverter (20 years old), I seldom use the 12 volt disconnect any more.

The factory installed burglar alarm in my 1996 U320 was using watts even though I did not have the key fobs so could not use it. I disconnected the power to it (as shown in the electrical diagram), but have not removed it because I cannot find it, although I did find the antenna.

I use the switch on the dash which was factory installed for the Audit System (replaced with See-Level) to provide power to the rear view monitor, the AM/FM/CD, and to the CB radio. I do have to reset the FM radio station presets every time I turn it on.

I reduced the mystery loads in my Foretravel from 6.5 amps to 0.6 amps. 

I also installed a switch for the 120VAC going to the entertainment area over the driver's head, and one for the bedroom TV. This reduces the load on the inverter for those times when I need inverter power but not for TV (most of the time).

Wyatt
96 U320 40 WTFE, build 4943
84 Toyota Supra towd
2015 Jeep Wrangler towd
Victoria, BC, Canada

Re: Phantom load sources?

Reply #13 –
I found one in the front tv compartment..

It's the solinoid switch that keeps the tv off while driving... attached to ignition lead hot..

Who would think the water pump on.. not running would take 1.8v
The selected media item is not currently available.
My advice and experiences are Free, you decide if they are worth anything .

John - driving Old Faithful
1994 U280 GV
C8.3, Banks, Pacbrake, 900 watts, Resonator, XLHD tow dolly
Retired Army Warrant Officer

Life is what you make of it - if it is lemons, make lemonade!
Former Coaches:
1988 GV 40' ORED 300HP CAT - 9 years
1990 Winnebago LeSharo - 3 years
2000 Newmar London Aire - 3 years (#18 of 23 produced)

Re: Phantom load sources?

Reply #14 –
Quote from: fouroureye –

Who would think the water pump on.. not running would take 1.8v

1.8 volts or amps?
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: Phantom load sources?

Reply #15 –
Brett... amps, sorry

Sice I disconnected everything to put a big tv there.. and drawers in place of the tv.. figured I'd be ok disconnecting it.
The selected media item is not currently available.
My advice and experiences are Free, you decide if they are worth anything .

John - driving Old Faithful
1994 U280 GV
C8.3, Banks, Pacbrake, 900 watts, Resonator, XLHD tow dolly
Retired Army Warrant Officer

Life is what you make of it - if it is lemons, make lemonade!
Former Coaches:
1988 GV 40' ORED 300HP CAT - 9 years
1990 Winnebago LeSharo - 3 years
2000 Newmar London Aire - 3 years (#18 of 23 produced)