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Topic: Odd sound from panel (Read 933 times) previous topic - next topic

Odd sound from panel

Recently there has been a rapid thumping sound coming from the circuit breaker panel in front of the passenger seat.  It seems to be associated with the air leveling system (comes on when air is below 110 psi).  Is anyone familiar with this?  I will try and isolate the circuit breaker.  My best guess is that a CB is tripping and resetting.
2000 U320 mid entry  #5688
2006 Jeep Liberty


USMCR retired
SDFD retired
FEMA US&R TF8

Re: Odd sound from panel

Reply #1 –
Sounds like you have properly diagnosed the noise.

After determining what breaker is making/breaking, next question is, is the circuit breaker getting weak, or is the load heavy enough that it should be tripping.  Tripping could be due to issue with the compressor, nick in the wire to the compressor going to chassis ground, etc.

Of course, verify that the breaker is the correct rating for the wire size/compressor amp draw.
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: Odd sound from panel

Reply #2 –
I located the source of the noise to the forward compartment below the front passenger seat.  It is the rectangular box which has a hose to the canister.  If anyone could identify what that is and its purpose, it would be really helpful.  I have opened the box, but am reluctant to detach the fitting on the right side of it, until I have an idea of what I am doing.  I've attached a photo.
2000 U320 mid entry  #5688
2006 Jeep Liberty


USMCR retired
SDFD retired
FEMA US&R TF8

Re: Odd sound from panel

Reply #3 –
That appears to be your vacuum generator and vacuum volume tank.

Pamela & Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Odd sound from panel

Reply #6 –
Here it is and how I repaired it. It controls the registers.

obsolete vacuum generator
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: Odd sound from panel

Reply #7 –
Looks like the problem is solved.  I found that air was getting by the hose/nipple connection (from vacuum generator to canister) whenever a certain amount of vacuum built up.  My theory:  The sudden drop of vacuum allowed it to "re-seal" until it quickly built up again causing a small jerk.  This translated into the thump when the box was attached to the compartment ceiling.  For some reason the PO detached the canister from the overhead bracket and that was easily remedied with two large hose clamps.  Two zip ties sealed the hose.  No more thumping.  If it re-occurs, I will try Craneman's remedy of replacing the blue check valve.
On a related issue, I was able to locate a wiring diagram which allowed me to make the correct switch connections and that solved the earlier problem I had with air volume and diversion.
Now if I can get motivated to wax the rig.  Maybe Richard Bark will help me when he gets back. :-)



2000 U320 mid entry  #5688
2006 Jeep Liberty


USMCR retired
SDFD retired
FEMA US&R TF8

Re: Odd sound from panel

Reply #8 –
Drive to Puerto Penasco MX

Eat fish, drink margaritas

watch local labor wax coach and polish wheels

drive home.

Tim Fiedler

Sure Start Soft Start

TCER Direct generator-gas-prod 630 240-9139
Gen-Pro
Tim Fiedler    2025 LTV Unity MBL on Order
2000 Chevy Tracker 2 Door Convertible 4WD Now lifted 4.5"
1985 Citroen 2CV6 Charleston
Murphy Rebel on wheels with 175HP Titan
Cessna P337
1980 48' Westport MY (!/4 Share)

Re: Odd sound from panel

Reply #9 –
Quote from: Tim Fiedler –
Drive to Puerto Penasco MX

Eat fish, drink margaritas

watch local labor wax coach and polish wheels

drive home.

Tim Fiedler

Sure Start Soft Start

TCER Direct generator-gas-prod 630 240-9139
Gen-Pro
Would be nice to find something closer - on this side of the border.
2000 U320 mid entry  #5688
2006 Jeep Liberty


USMCR retired
SDFD retired
FEMA US&R TF8

Re: Odd sound from panel

Reply #10 –
Sven, I'll help you with that, if you'll help me change out my house batteries😀😀
Richard & Betty Bark & Keiko our Golden Doodle
2003 U320T 3820 PBDS
Build # 6215
MC # 16926
2016 Chevrolet Colorado 4X4 diesel

Re: Odd sound from panel

Reply #11 –
Quote from: rbark –
Sven, I'll help you with that, if you'll help me change out my house batteries😀😀
It's a deal Richard, but I'll be done before you get back.
2000 U320 mid entry  #5688
2006 Jeep Liberty


USMCR retired
SDFD retired
FEMA US&R TF8