2012 reyo, only start on Battery boost

[Reyo2012]

Had emissions Recall done on 2012 Itasca Reyo. Got 3 miles from dealerstopped for fuel. When I got back in, coach wouldn't start. Had to you use battery boost button, to start Coach. Called dealer. They said the Chassie battery was probably low because they had been working on it without running it a lot. So I drove the hour and a half to home. When I got home, I tested the battery. It showed cold cranking amps were just below the Rating on the battery. So I pulled the battery and found out that it was 10 years old. So I replaced it.. But still won't start without using battery boost. I have cleaned all the connections, tested the new battery, it has 870 cold cranky amps. I have checked all the wires for any sign of breakage, but can find none. Have tried to start using a jumper pack, at remote connection, under the hood, and rite on battery, but coach won't crank, either way. But still cranks, using the boost button.
Has anyone else had this problem? Does anyone have any idea how the starter is wired, (is there some way the chassis battery is isolated from the connection, with the boost button ) so I might find a relay or something, that is a disconnect in that system. Any help would be helpful.i have got a wiring diagram from Winnebago, but it shows boost button, but nothing else. Thanks

[bigb]

Check your chassis battery disconnect down by the accelerator pedal, make sure it is firmly pushed onto the stud and the stud is tight. The wiring diagram from Winnebago only shows what they added, for the main starter circuit you need the Sprinter diagram.

[Morich]

You have proven out that most of the starting syustem is okay, just not the cables or battery for the last bit. I suspect you are missing one or more points on checking the cables for corrosion but that needs some testing to prove.
With a meter, first look at the start battery connection on the post itself, then compare that reading with what you get on the clamp and they should be very close to the same voltage if the connection is good.
Then while there, set the meter to test resisance, press the two leads together to see how much resistance is in the leads and to make sure the meter is set right. Then go on the frame, etc to get a good clean ground and test the negative post of the battery with the other lead. Those two readings should be very close to the same if the ground lead to the battery is good.

Move to the starter and do the same check for voltage on the starter post and then on the cable end. If they read the same or very close to what you had at the battery, the positive cable is good.

Check the ground cable the same as at the battery and it should be very low resistance if it is a good connection. Check the post on the battery and the cable end to compare and see they are actually making connections .

There are connections at the mode solenoid but you have proven them good by being able to change the starting when pressing the boost switch.
A bit of info to clear that question may help.
At the dash area, there is a wire called LR that sends power down to the solenoid when the ignition is on or we push the button. There is also a wire FM which is ground going to the solenoid. This battery and ground is proved working as they are what make the solenoid close and connect the coach and start battery together to help the engine start.
We can call them good because they do what you want when pressing the switch!
Very simple place but one which can cause lots of folks trouble when the solenoid gets worn as it keeps the coach from charging while we drive!

Mode solenoid is not the problem as the power is not getting from the start battery to the starter without using the solenoid. Reason for starting when pressing the switch is that you DO get power to the starter but it is becasue it is then connected to the coach batteries, not the start getting there.
Possible causes seem to be:
Low /bad battery--you seems to have covered that.
Poor connection on battery cable from battery to starter. May need more checking as there may be some hidden point not found.
Poor ground connection at starter but I lean away from that due to working when coach battery is connected.
Possible poor starter solenoid may be not giving totally good connect at times??

This snip from the drawing shows the solenoid. Click to get a better view.



Blue are thw two wires from boost switch yellow cables will be makrked with yellow tape at ends and red cables marked the same. This is where the yellow cable from coach and red from start connect together inside the solenoid. But this is working okay.
Your problem seems to be in the cable from the start battery to the starter solenoid and on to the battery. Those are part of the chassis builders job and not shown on the Winnebago part!
An item which might be missed is there are mega fuses along the route at times and places we might not look. those have connections at each end and may be aproblem.
On the Vista, that fuse was under a rubber cover directly behaind the front passenger side wheel and a really bad spot for corrosion! Possibly try to spot where the slide or jacks connect into the cable to the starter as being a suspect?

[Reyo2012]

Brian,
Thanks. I have already checked the connection, by the accelerator. It's good. I even sprayed both the stud & the plug with contact cleaner. I even went 1 step farther & ran a jumper cable, from the negative terminal on the battery, to a good ground, to make sure the cable from battery to the ground stud was good. Will let you know what I find in the end.
Duffy

[Brooks]

Had the exact same problem and it ended up being the bolt that held the 2 positive wires to the battery post clamp

[Morich]

An easy habit that may save some time if we do it, is the way we test the cables and connections.
When we use a meter and look at the battery voltage, we can spot any corrosion with the meter if we simply test BOTH the battery post as well as on the battery cable end.

When we think about it, the post and the ends should be connected directly together and the voltage reading should be very near the same. So if we check both and one is lower, the only way that can happen is if they are NOT well connected!

Those mega fuses I mentioned or any connection like an isolated stud where two cables connect is a place which we can miss as they may not be near the battery or where we are looking for them.

On the 2015 Vista 31KE late build, the mega fuse was outside the battery box, mounted on the frame just behind the front wheel where it caught losts of water off the wheel.
It was also where I never expected it!!



I checked the voltage was good on the post and also on the clamp of the cable headed toward the mode solenoid but found it did not have the same voltage at the solenoid. Kind of simple thinking that if we put water in a hose at one end, it should come out the other! So I knew there had to be a bad connection along the line somewhere.

The reason I want to stress testing and looking for mega fuses is how easy it is to miss them.

This is the type I found.


With a rubber type cover, behind the wheel and a few years of road oil, dirt, and mud, it really blended in and hid!

With a cable going in one end and out the other, there are lots of chances for this little bear to cause trouble!!
I was lucky in it being on the coach wiring where we did have a better chance to look at the drawings and find where they hid things. Had it been on the start battery side, we get less of the really good drawings and have to hunt!

Big point is that we know that we have something going open if we put voltage in one end and it doesn't come out the other!!

[Reyo2012]

Originally Posted by Brooks

Had the exact same problem and it ended up being the bolt that held the 2 positive wires to the battery post clamp

Brooks, i Checked all connections,removed all wires, cleaned & reconnected. Checked for voltage loss, then checked continuity. All good. Thanks for your input.

[Reyo2012]

Originally Posted by Morich

An easy habit that may save some time if we do it, is the way we test the cables and connections.
When we use a meter and look at the battery voltage, we can spot any corrosion with the meter if we simply test BOTH the battery post as well as on the battery cable end.

When we think about it, the post and the ends should be connected directly together and the voltage reading should be very near the same. So if we check both and one is lower, the only way that can happen is if they are NOT well connected!

Those mega fuses I mentioned or any connection like an isolated stud where two cables connect is a place which we can miss as they may not be near the battery or where we are looking for them.

On the 2015 Vista 31KE late build, the mega fuse was outside the battery box, mounted on the frame just behind the front wheel where it caught losts of water off the wheel.
It was also where I never expected it!!

Attachment 184851

I checked the voltage was good on the post and also on the clamp of the cable headed toward the mode solenoid but found it did not have the same voltage at the solenoid. Kind of simple thinking that if we put water in a hose at one end, it should come out the other! So I knew there had to be a bad connection along the line somewhere.

The reason I want to stress testing and looking for mega fuses is how easy it is to miss them.

This is the type I found.
Attachment 184852

With a rubber type cover, behind the wheel and a few years of road oil, dirt, and mud, it really blended in and hid!

With a cable going in one end and out the other, there are lots of chances for this little bear to cause trouble!!
I was lucky in it being on the coach wiring where we did have a better chance to look at the drawings and find where they hid things. Had it been on the start battery side, we get less of the really good drawings and have to hunt!

Big point is that we know that we have something going open if we put voltage in one end and it doesn't come out the other!!

Richard, thanks for the help, all connections were good. After hrs of chasing many leads, trying different things, I called a large RV dealer/repair shop. They gave me some past findings. I checked them out, with no success.
I finally called dealer for 1 more try(called 8 times before, looking for info/ideas). Left message for general manager. He didn't call, but he had top mechanic call me) after 15.minutes of me telling him, that there was a loss of power, to the solenoid, and that the boost button was supplying power, somehow thu backdoor. But I couldn't find that backdoor without a schematic. He told me if I wanted to bring it back to dealer (over 90 minutes away) he would bring it right in to try troubleshooting it for me. I kept telling him my backdoor theory, in different ways, asking different questions, he said: " you know, years ago, we had a problem, like that, and found that the starter motor fuse, was blown. It was a 20amp, we had to up it to 30 amp. "
I didn't get a owners manual, for the Sprinter chassis, so I downloaded one. I searched "FUSE" in the index, found the position 23 fuse was labeled- "STARTER MOTOR". I Checked that fuse, and it was blown. I replaced it, COACH NOW STARTS! I replaced it with same size (20amp), but will start Coach, numerous times, the next few days, to make sure, that fuse doesn't blow again! ��

THANKS TO ALL FOR YOUR INPUT! HAPPY NEW YEAR, AND
GOD BLESS YOU!

[tim myers]

WOW, that was the proverbial needle in the haystack for sure.

[bigb]

There is a TSB on that fuse with instructions to change it, I believe to a 25 amp. I have the TSB hanging in my shop, when I get out there today I will take a pic.

[Morich]

Glad to hear it run down. One of the big things on our RV is that we get lots of good info on the coach/RV things that Winnebago adds but the chassis folks often hold that info very close as they want the repair business for their shops.
If there is now a move to force better service on cell phones, it may be way past time to force better info from the automotive end as well?

NEVER happen!

[bigb]

Here is the TSB for model year 2010, your 2012 Reyo likely has a 2011 chassis and is probably identical to the 2010. The TSB states 2500 chassis however there is no difference in the engine or starting circuit between the 2500 and the 3500. I was not aware that the boost switch bypassed the chassis starter fuse, this is good to know for future reference as had I known that I could have steered you in the right direction sooner.

[creativepart]

I’ll bet this is covered completely at the Sprinter Forum. I never even thought about the Reyo being a Sprinter-base RV.

https://sprinter-source.com/forums/index.php

[bigb]

Originally Posted by creativepart

I’ll bet this is covered completely at the Sprinter Forum. I never even thought about the Reyo being a Sprinter-base RV.

https://sprinter-source.com/forums/index.php

Yes it was discussed over there but as the vast majority of members do not have motorhomes the fact that the boost bypasses the fuse was not discovered or mentioned, this may very well be the first mention/discovery of it on the internet and we are now empowered with a little known piece of Sprinter knowledge!

[Morich]

That really seems like a built-in case of head scratching! A fuse for the starter but it also has a bypass route if the boost switch is used?
I can see using a fuse but then having a bypass for that fuse seems to really make the fuse debatable. What is the fuse meant to protect if there is a handy route around the fuse to give it more power?
If a 20 is not big enough, going to a 25 seems really cutting it close.
But then I am not an engineer nor designer and I often wonder at things they do!

[bigb]

Originally Posted by Morich

That really seems like a built-in case of head scratching! A fuse for the starter but it also has a bypass route if the boost switch is used?
I can see using a fuse but then having a bypass for that fuse seems to really make the fuse debatable. What is the fuse meant to protect if there is a handy route around the fuse to give it more power?
If a 20 is not big enough, going to a 25 seems really cutting it close.
But then I am not an engineer nor designer and I often wonder at things they do!

Well the chassis was designed by German engineers and the coach by, well, Winnebago. Need I say more?

[Morich]

Yup! The cartoon about the swing comes to mind!
Evrybody talks to the other folks but nobody listened to anything that was said!