Mechanically Inclined Newbie w/LOTS of PROBS! But I love my 39Z DP Bounder

First time MH owner.  Mech inclined (luckily) and also have no money so I gotta roll up my sleeves. 

I purchased my Bounder 39Z DP, March of 2017 to live in full-time. 

I bought a go-power 120watt portable solar system that I'm in process of upgrading to a 1Kw with a very expensive battery pack.  I want to run one A.C off solar. 

It has a Onan QD 7500  that I normally can't start without pressing and holding the Aux By-Pass button.  But it does start right up and run without issues 95% of the time.  Sometimes it dies 3 times in a row after a few mins and then runs fine for 100's of hrs.  It doesn't blow any blue/black smoke (I saw it do it once for a few seconds right after I started it). Today it stopped running after being on or 20+hrs and I got an error code 17 (first time it ever just died that wasn't because I ran out of fuel and I'd just filled the tanks last night so that wasn't the reason. Code 17 isn't listed anywhere and it started right up and has been fine since.  I checked the under the hood and the oil fill & coolant caps weren't twisted shut and the passenger side front of it has rusted so much so that I feel wind blowing through the rust.  I got my roll of 5 inch Gorilla tape and sealed it all the way around.

The Inverter was upgraded from a COMBI to a SW3012 but they forgot the panel (and the genny assist) and the temperature charge sensor was double side taped to the wall of the battery box. 2 12 volts in parallel not 4 6's like it should be. 

I have no idea where my water / fuel separator is and I've missed about 150 days of emptying it.  Hope it's not important. 

When changing the oil I found a 2nd "oil filter" on the passanger side that looks exactly like the one on the drivers side.

Up at the nose, under the coach, about where the captains chairs are above, there is what looks like a big car radiator with a fan that I've never seen do anything. 

It is supposed to have a 90 gal diesel tank capacity but I've never been able to buy more that 70 gals when bone dry. 

When looking down on the exhaust system from the bedroom, I can see through many spots that are rusted out although it's not crumbling or falling apart at all - it seems very solid. 

The other day, shortly after starting it, I heard what I thought was the jacks retracting, hitting the base hard, but it was really loud.  I got out and a friend was there too.  We both walked around to the back to be greeted with what sounded like a gunshot, then again 10 secs or so later.  It's not happened since and I'm thinking that - because it wasn't run for a few days and it's been very very humid, the air pressure release valve was sticky / sticking.

There are the remants of several aftermarket towing solutions under the dash along with something called "Tire Secure".  When I lifted the instrument cluster I was shocked by how poorly these things were installed.  There's exposed 'hot' wires everywhere tapped into God only knows what systems.  The other day by map lights above the dash and my 12volt lighter outlets stopped working and I don't know why...

Last but not least, when driving, no always but 80/90% of the time, the closer I get to 73mph, the more violent the front end shakes up and down.  I can let go of the where and it goes dead on straight.  When I pass the 73 mph mark it starts to smooth out the further I get from it AND LIKEWISE WHEN SLOWING DOWN THE WHOLE THING STARTS AGAIN!!! AAHHH!! It's like it oscillates through the coach.  I gets better the moment I get pass 73.  The tires are from 2010.  The shocks do NOT get warm - I'll drive for 30 mins, hop out and reach under and grab them as test to see if they're shot.  Was suggested if they're cold they're not absorbing shocks and should be replaced.  I've balanced, the alingned and rebalanced the front end all within a few days and it made it better.  Now its suggested that I replace the shocks and then tires if it doesn't fix it.

AS WITH ALL THAT I'VE DESCRIBED I'M OPEN TO INTELLIGENT SUGGESTIONS!  

Many thanks,

Vince
Vincent Louis Marino - Facebook

Welcome Vince!  Sounds like you have your hands full with your first rig there, but in certain ways... it's all part of RV'ing. 

I moved your thread here to the "Motorhomes" area of the forum, where I think your questions above will get more views and responses.

Hi Vince, welcome to the forum.  I suggest the first thing you need to do is get the entire exhaust system checked by a competent shop. I had a neighbor whose coach caught fire twice. The first time it was blamed on an electrical problem because his whole battery compartment burned up... batteries,  converter, transfer switch, power cord and the metal compartment box itself.  He got it all repaired at a shop $12k+. He was from Toronto,  Canada. He left early one morning head back to Toronto.  By 10 am he was back--same problem, another fire. Well, the shop eventually found a hole in an exhaust pipe.  The hole was aimed directly up at the battery compartment.

I've never seen or heard of an AC unit running off of Solar or batteries for more then a few minutes if it even could start up.
Solar can power a lot of things - but not AC.  Your generator can.

IMO even thought it may be legal for you to drive above 70mph it not a good idea to do so.
MH's don't stop as fast as cars can and moving a house down the road is harder on it the faster you go.
Not to mention the poor fuel economy.

Are you positive that you have 2 oil filters - Same exact numbers on both?
It's more common to have 2 fuel filters - a primary and a secondary.

Where you really bone dry?  It's a bad thing to let a diesel run out of fuel.  Maybe the gauge is not accurate.
On my coach the fuel gauge doesn't move as far as the amount of fuel I have used.
Most generators are set to stop running when ? tank of fuel is left - to keep you from being stranded.

PCMatters said:

Last but not least, when driving, no always but 80/90% of the time, the closer I get to 73mph, the more violent the front end shakes up and down.  I can let go of the where and it goes dead on straight.  When I pass the 73 mph mark it starts to smooth out the further I get from it AND LIKEWISE WHEN SLOWING DOWN THE WHOLE THING STARTS AGAIN!!! AAHHH!! It's like it oscillates through the coach.  I gets better the moment I get pass 73.  The tires are from 2010.   

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Welcome. You're not going to want to hear this but IMO, the first thing you must do is slow down for your safety and everyone's else's safety around you. Your tires are 7 years old and you should think about replacing them even if then tread looks like new. Tires start breaking down from the inside. How fast would you drive if you could get beyond 73 MPH. Slow down and enjoy the ride.

I see a lot of potential issues in this report and I hardly know where to start! I'll try to hit the highlights, but each of them is likely to trigger a long debate on its own.

I bought a go-power 120watt portable solar system that I'm in process of upgrading to a 1Kw with a very expensive battery pack.  I want to run one A.C off solar. 

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A very impractical desire, IMO. Each a/c units uses 1200-1440 watts per hour and runs much of the day and evening in any warm climate. You need a huge battery bank and a large solar array to even attempt it. Do the arithmetic of consumption vs stored power and you will see this is true.

It has a Onan QD 7500  that I normally can't start without pressing and holding the Aux By-Pass button.

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That says your chassis batteries are poor or there is a poor connection between them and the genset. That genset in this coach starts from the chassis batteries, but the Aux switch places the house batteries in parallel with them for increased power.

...the temperature charge sensor was double side taped to the wall of the battery box. 2 12 volts in parallel not 4 6's like it should be.

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Place the sensor between any two house batteries, or tape to the side of one of them.
Two 12v is a common set-up. more expensive rigs may have larger battery banks as standard, but two 6v's or 2 12v's is common in lower end models like the Bounder. You should buy and install the number of amp-hours you need. Battery size and voltage Can differ according to your needs and budget. See my article on RV battery choices at Choosing a battery

I have no idea where my water / fuel separator is and I've missed about 150 days of emptying it.  Hope it's not important.

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Not terrible important unless there is a fuel tank problem, but it's something you need to know.  It should not be hard to find. Follow the fuel line and a filter canister should be visible, though you may have to get underneath. You will need to change the fuel filter periodically anyway because they do catch dirt and sometimes algae and need to be changed. Annually is probably a wise choice, but you can wait until the engine loses power to do it.

When changing the oil I found a 2nd "oil filter" on the passanger side that looks exactly like the one on the drivers side.

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Perhaps that is the fuel filter & separator you were looking for? The engine has only one oil filter.

Up at the nose, under the coach, about where the captains chairs are above, there is what looks like a big car radiator with a fan that I've never seen do anything.

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Not sure what that is. Maybe a condensor for the dash a/c?  Or the genset radiator? But an Onan 7500 has its own radiator in its housing and fed by air from underneath. By the way, the genset has an air filter, oil filter and fuel filter too. All need periodic changes.

It is supposed to have a 90 gal diesel tank capacity but I've never been able to buy more that 70 gals when bone dry.

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90 gallons is the capacity of the tank on a laboratory bench.  When plumbed into the RV, it typically has less usable capacity.

The other day, shortly after starting it, I heard what I thought was the jacks retracting, hitting the base hard, but it was really loud.  I got out and a friend was there too.  We both walked around to the back to be greeted with what sounded like a gunshot, then again 10 secs or so later.  It's not happened since and I'm thinking that - because it wasn't run for a few days and it's been very very humid, the air pressure release valve was sticky / sticking.

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The sound of the air dryer and air pressure relief valves popping off. Normal, but if it does it repeatedly or when coming to a stop, have the air system serviced and checked for leaks.

the closer I get to 73mph, the more violent the front end shakes up and down.  I can let go of the where and it goes dead on straight.  When I pass the 73 mph mark it starts to smooth out the further I get from it AND LIKEWISE WHEN SLOWING DOWN THE WHOLE THING STARTS AGAIN!!! AAHHH!! It's like it oscillates through the coach.  I gets better the moment I get pass 73.

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Classic symptoms of poor tire balance and/or possible severe alignment problem.  The other possible cause is tread separation within the tire, a condition that will only show up on the highway and not on a balance machine or alignment machine.

The tires are from 2010.

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Getting old and the probability of a blowout is getting high. 10 years is the max usable life, regardless of tread wear or visible condition, and  the risk of a blowout increases substantially in the 7-10 range. A blowout on a motorhome almost always cause significant body, wiring or plumbing damage.

Your fuel filters will also not be the same part number,, as the the first inline filter from the tank will be the "primary" filter,(many times will also have a water separator system attached to the bottom),, the second will be the "secondary" which will have tighter filter tolerances before reaching the high pressure pump and injectors that REQUIRE clean and water free fuel. The "big car radiator" is the condenser and fan for your dash air system and comes on when in use and at certain temps..You stated that you bought the M/H in 17, but did not state the year of manufacture,,this would help when soliciting info.>>>Dan

Sorry for your repairs. Not sure if you had this Bounder inspected before you bought it, but unfortunately it looks like you are going to have to invest  a lot of money to make it right. Not sure of your skills, but it looks like you will have to take it to professionals for some of the work.


Bill