SCOPE 18M Inverter

[PaddyWagonTravels]

Hello, all,

I have been reading the forums to see if there is an answer to my question. Before anyone asks, I have read through all of the owner's resources but cannot get an answer to my question. I recently brought the unit in for service. It was there for about a week and I believe it was kept in the garage stall. Was not plugged in and not getting any solar. When I picked up the unit and got it home, I noticed my inverter light was off. I pressed the button to turn it back on and nothing happened. I tested the GFI, and tore the bed unit apart to locate the inverter (it is under the bed covered up by Truma heating ducts and not reachable). Finally took apart the entire bed frame and still could not see any switches where I could recycle the inverter. I unplugged it and then plugged it back in, but still nothing. Any help on this would be great. The unit is a 2023 and I cannot believe the inverter is dead. Outside of bringing it back in for service - is there anything I am missing and can do? Thanks in advance for any help.

 

[16ACE27]

The inverter won't turn on if the batteries are dead.

 

[Mark54]

Hello, all,

I have been reading the forums to see if there is an answer to my question. Before anyone asks, I have read through all of the owner's resources but cannot get an answer to my question. I recently brought the unit in for service. It was there for about a week and I believe it was kept in the garage stall. Was not plugged in and not getting any solar. When I picked up the unit and got it home, I noticed my inverter light was off. I pressed the button to turn it back on and nothing happened. I tested the GFI, and tore the bed unit apart to locate the inverter (it is under the bed covered up by Truma heating ducts and not reachable). Finally took apart the entire bed frame and still could not see any switches where I could recycle the inverter. I unplugged it and then plugged it back in, but still nothing. Any help on this would be great. The unit is a 2023 and I cannot believe the inverter is dead. Outside of bringing it back in for service - is there anything I am missing and can do? Thanks in advance for any help.

Assuming you have a Combimaster, and batteries are dead.

One remedy it to plug into shoreline, and then go to driver's seat, and briefly hold the emergency start switch for a bit- like 10-20 sec. (engine off)

If batteries are dead- they may need some "CPR" from the chassis battery (aka jump start)

If that fails, There is a cover over the end that hides the wire connections- remove the two phillips head screws on the end (one seen in pic- other is on the r. corner)
Slide cover off and set aside.

Then remove the large battery B+ cable- DON"T LET GO OF IT- count to 10, and then reconnect it.(might spark a little- is ok)

If that cable contacts anything other than it's connection point, then you could have fireworks...!

Rocker switch seen in 1st pic should be "Charge only" position. (On is for the inverter part)

Then plug into shoreline power and see if that works. Might take a few minutes to 'wake up'. Try e-start switch again.

Hope that helps.
Keep in mind the chassis battery may not charge when plugged into shoreline if you have the lithium battery/ under-hood generator.

PM me for more about that if you need. I keep a trickle charger on mine if it sits more than 3 days.

 

[PaddyWagonTravels]

Sorry about that. The batteries were not dead, but they were low. I plugged in the unit to shore power and the batteries recharged. The inverter will not come on.

 

[PaddyWagonTravels]

Thanks - this helps a great deal, but probably a little more involved for me to deal with so off to get it serviced.

 

[Mark54]

Sorry about that. The batteries were not dead, but they were low. I plugged in the unit to shore power and the batteries recharged. The inverter will not come on.

Inverter won't come on until the battteries are up to snuff, so wait before going to dealer- sounds like it may self-resolve.
Inverter can be turned on at Mastervolt panel, or on the inverter itself (much harder when under a deck, so use the MV panel) Bottom right button- will say "Inverting" when batteries can deliver the power.

 

[PaddyWagonTravels]

Inverter won't come on until the battteries are up to snuff, so wait before going to dealer- sounds like it may self-resolve.
Inverter can be turned on at Mastervolt panel, or on the inverter itself (much harder when under a deck, so use the MV panel) Bottom right button- will say "Inverting" when batteries can deliver the power.

Thank you, Mark. I do not see a Mastervolt display anywhere. All I have is the remote inverter switch, which does nothing when switched on. I do have some equipment under the sink that includes the Master RV solar controller but I do not see a Mastervolt in this collection of equipment.

 

[Mark54]

250A ANL fuse for Tellaro,Sequence, Scope, Rize

Thank you, Mark. I do not see a Mastervolt display anywhere. All I have is the remote inverter switch, which does nothing when switched on. I do have some equipment under the sink that includes the Master RV solar controller but I do not see a Mastervolt in this collection of equipment.

Interesting- well, if you had it would be over the slider or by master switch as mine is- looks like this- black panel, top right here (modified panel)
Glad you have the remote switch- mine did not have, so I added one to not have to use the MV one up front at night.
When the batteries reach full charge, should work again- OR...
Your 250A fuse may be blown- under the coach aft of the batteries that is connected to the inverter's B+ cable. So that will have to be looked at if the inverter doesn't respond. Seen in 2nd photo, center of pic. Also a 50A for the 12V system. Have dealer check these. Hopefully dealer is a good one... Unlikely that is blown if batteries are charging. But you should know where these devices are. Look at the 50A breaker as well- controls voltage to 12V panel.

While they are in there- have them double check the dipswitch settings for the Inverter. Many are incorrect- assuming you have lithium batteries, has to be set for those.


One has to wonder why they decided to put those in a place no one would ever look.

I moved all that up inside mine as I don't especially like crawling in mud to find a blown fuse!! Batteries came up too- and upgraded from 200a to 600A. All under my pass. side bed cabinet now.

 

[16ACE27]

Interesting- well, if you had it would be over the slider or by master switch as mine is- looks like this- black panel, top right here (modified panel)
Glad you have the remote switch- mine did not have, so I added one to not have to use the MV one up front at night.
When the batteries reach full charge, should work again- OR...
Your 250A fuse may be blown- under the coach aft of the batteries that is connected to the inverter's B+ cable. So that will have to be looked at if the inverter doesn't respond. Seen in 2nd photo, center of pic. Also a 50A for the 12V system. Have dealer check these. Hopefully dealer is a good one...

One has to wonder why they decided to put those in a place no one would ever look.

I moved all that up inside mine as I don't especially like crawling in mud to find a blown fuse!! Batteries came up too- and upgraded from 200a to 600A. All under my pass. side bed cabinet now.

Hey Mark! You're much more an expert on these Bs than me, but here's a thought:

Being at the dealer with no source of charge and likely the inverter and maybe other loads left on - it seems the batteries were completely drained to the point the BMS shut them off (and kept them off).

Is the charger too smart and now doesn't see the batteries connected so although plugged into SP, the batteries won't charge until "jumped" to force the BMS to turn them back on (and the charger to charge)?

 

[Mark54]

Hey Mark! You're much more an expert on these Bs than me, but here's a thought:

Being at the dealer with no source of charge and likely the inverter and maybe other loads left on - it seems the batteries were completely drained to the point the BMS shut them off (and kept them off).

Is the charger too smart and now doesn't see the batteries connected so although plugged into SP, the batteries won't charge until "jumped" to force the BMS to turn them back on (and the charger to charge)?

Yes, the BMS will shut them down, and by using the e-start switch, voltage is diverted from chassis battery to coach batteries to 'jump' start them. (previous post)
I also added that 250A breaker is unlikely to be the culprit if they are charging. 50A lever style breaker is suspect tho. All need to be looked at and verified, along with DIP switch settings on Combimaster inverter.

I'm not optimistic about dealer knowing the tricks like this one.

Putting all this under the chassis is a disaster for the owners of these rigs. I am so glad I spent the 5 days to move it all up inside- so much easier to manage now.

 

[Mark54]

Thank you, Mark. I do not see a Mastervolt display anywhere. All I have is the remote inverter switch, which does nothing when switched on. I do have some equipment under the sink that includes the Master RV solar controller but I do not see a Mastervolt in this collection of equipment.

Two other bits of advise:
1) Carry a jumper battery (Noco "boost" shown) for the chassis battery (under your feet, so hard to reach- see my pic for jumper posts under bonnet/hood)
I have jumped other RV-er's at campsites too with the Boost pack. Nice to have and better than jumpers as you don't need cables or another vehicle!
Jumper battery (has light too!)- just be sure it's fully charged before leaving...
https://www.amazon.com/gp/product/B07MVY7K43/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

2) As mentioned keep a 2A trickle charger connected any time you are parked for 3+ days as the chassis battery will simply die. See pics.
Trickle charger found here:
https://www.amazon.com/gp/product/B07W6B987F/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

 

[MCP-THOR]

Yes, the BMS will shut them down, and by using the e-start switch, voltage is diverted from chassis battery to coach batteries to 'jump' start them. (previous post)
I also added that 250A breaker is unlikely to be the culprit if they are charging. 50A lever style breaker is suspect tho. All need to be looked at and verified, along with DIP switch settings on Combimaster inverter.

I'm not optimistic about dealer knowing the tricks like this one.

Putting all this under the chassis is a disaster for the owners of these rigs. I am so glad I spent the 5 days to move it all up inside- so much easier to manage now.

I took a quick look at the Thor website Scope info. I'll take a wild guess that if the OP has the standard setup, he has a 1000w inverter and not the Mastervolt Combimaster inverter/"charger". Also, 2 AGM batteries. I believe there is no AC input to the inverter, only an outlet plug. So, no charging by the inverter itself, correct? If you go to the Mastervolt site (assuming his inverter is Mastervolt) you can view and download the specific manual. It shows dip switches and main on/off switch, etc.

So, either it is switched off at the unit, or as Mark says, there's a breaker disconnect. As OP indicated in earlier post, batteries are now charging.

I have no answers, only guesses!

 

[Mark54]

I took a quick look at the Thor website Scope info. I'll take a wild guess that if the OP has the standard setup, he has a 1000w inverter and not the Mastervolt Combimaster inverter/"charger". Also, 2 AGM batteries. I believe there is no AC input to the inverter, only an outlet plug. So, no charging by the inverter itself, correct? If you go to the Mastervolt site (assuming his inverter is Mastervolt) you can view and download the specific manual. It shows dip switches and main on/off switch, etc.

So, either it is switched off at the unit, or as Mark says, there's a breaker disconnect. As OP indicated in earlier post, batteries are now charging.

I have no answers, only guesses!

"Guessing" is how the process starts!

I am not sure what the Scope has, OP has to tell us more, but most of that year have lithium/UHG setups, but need verification by "PaddyWagonTravels".
Dealer sure doesn't know- esp. after keeping it that long and handing back to owner discharged! I wouldn't go back (and don't anyway)
Pictures help a lot too, as you can tell by my posts- I don't advise w/o a pic as long as I have one for that subject.
I just looked it up- my bad...

Yes- AGM's generator and a 1000W inverter, so any of my advice is out the window! Check breakers first.
If AGM, and low voltage, could be damaged as they can be damaged if discharged to 0%.

https://poweringautos.com/does-an-agm-battery-get-damaged-if-low-charge/


If dealer had on the lot and let them get that way- then they are liable!

 

[PaddyWagonTravels]

I took a quick look at the Thor website Scope info. I'll take a wild guess that if the OP has the standard setup, he has a 1000w inverter and not the Mastervolt Combimaster inverter/"charger". Also, 2 AGM batteries. I believe there is no AC input to the inverter, only an outlet plug. So, no charging by the inverter itself, correct? If you go to the Mastervolt site (assuming his inverter is Mastervolt) you can view and download the specific manual. It shows dip switches and main on/off switch, etc.

So, either it is switched off at the unit, or as Mark says, there's a breaker disconnect. As OP indicated in earlier post, batteries are now charging.

I have no answers, only guesses!

Thank you all for this great conversation. To your point MCP, I was able to locate the actual manual for my inverter and I believe the front switch is off. I have a green light on the front of the inverter indicating pass-through power, but it should be amber-colored when inverting. Sadly, there is so much equipment crammed in this space, I will need to remove the Truma heating ducts in order to reach the switch - which should be in the off position to power the remote power switch. Anyway - a great thanks to everyone for your help.

 

[PaddyWagonTravels]

"Guessing" is how the process starts!

I am not sure what the Scope has, OP has to tell us more, but most of that year have lithium/UHG setups, but need verification by "PaddyWagonTravels".
Dealer sure doesn't know- esp. after keeping it that long and handing back to owner discharged! I wouldn't go back (and don't anyway)
Pictures help a lot too, as you can tell by my posts- I don't advise w/o a pic as long as I have one for that subject.
I just looked it up- my bad...

Yes- AGM's generator and a 1000W inverter, so any of my advice is out the window! Check breakers first.
If AGM, and low voltage, could be damaged as they can be damaged if discharged to 0%.

https://poweringautos.com/does-an-agm-battery-get-damaged-if-low-charge/


If dealer had on the lot and let them get that way- then they are liable!

Thanks for your help, Mark - the SCOPE (mine at least) has AGM batteries with the 1,000 watt inverter. The batteries are holding a charge, but it is clear the batteries need to be replaced. The unit is 2023, I bought it used. Again, these conversations have been very helpful.

 

[Mark54]

Thanks for your help, Mark - the SCOPE (mine at least) has AGM batteries with the 1,000 watt inverter. The batteries are holding a charge, but it is clear the batteries need to be replaced. The unit is 2023, I bought it used. Again, these conversations have been very helpful.

Most welcome!

If your devices can be configured to lithium, might be time to consider switching. LiFePO4 batteries (aka LFP) are safer than Li-ion and need 14.6V to charge instead of 14.2 for AGMs. So see if your converter, solar controller, and inverter can all be set for Li batteries first. can Be $ to change, but is worth it if you do any degree of boondocking as we do.

So find your manuals and start reading to see if that can be done w/o replacing those components. Many devices like these have "DIP" switches that you can change for each type of battery, or a dial that you change.

Happy New Year!!
Mark

 

[PaddyWagonTravels]

Most welcome!

If your devices can be configured to lithium, might be time to consider switching. LiFePO4 batteries (aka LFP) are safer than Li-ion and need 14.6V to charge instead of 14.2 for AGMs. So see if your converter, solar controller, and inverter can all be set for Li batteries first. can Be $ to change, but is worth it if you do any degree of boondocking as we do.

So find your manuals and start reading to see if that can be done w/o replacing those components. Many devices like these have "DIP" switches that you can change for each type of battery, or a dial that you change.

Happy New Year!!
Mark

Thanks again, Mark, and Happy New Year to you as well.

 

[Mark54]

Thanks again, Mark, and Happy New Year to you as well.

PM replied to- thanks!

 

[WhatnxtRV]

Have you contacted Thor CS to hear what they say?

Happy New Year to all.

 

[WhatnxtRV]

PaddyWagonTravels:

So, what was the outcome?

I have the same RV.

Thank you.