Citation 24SS 2918 battery cables

[Neil - submariner]

I screwed up by not shooting a “before” picture - but it didn’t seem complicated until it does.

I am attaching pics.

Does anyone have a pic of their house battery cable hookup for this Class C?

What’s been confusing is the wiring - a number of red cables (with black electrical tape wrapped around it at 3 inch intervals) we’re attached to the gnd post. That would indicate a black wire in the building industry. But then I see time and again that only red and black wires on an RV should go black positive and red negative. If that’s the case why are 4 wires attached to a ground post?

Now I have two other loose cables, one black and the other red. The red appears to be AWG2 and the black maybe a AWG 4. If I use the convention above the smaller wire would be attached to the positive post and the larger wire to the negative post.

Do you see why this is confusing?

Any and all help appreciated. Thor Sent electrical diagrams but they are difficult to read.

Neil

[16ACE27]

Yep, that before picture with marked cables would be pretty handy now.

You might have to do some wire tracing to get this right. You should have:

2 Jumper cables to connect + to + and - to -
1 ground cable that goes directly to a frame connection
The rest should be positive cables to:
a 50 amp DC breaker for DC house loads and converter charging
a 100 amp DC breaker for generator starting (and levelers if equipped)
the BIM which cross connects to the chassis battery
the solar charger (if equipped) - smaller gauge cable

Hopefully this helps!

ETC/SS Retired

[Neil - submariner]

Originally Posted by 16ACE27

Yep, that before picture with marked cables would be pretty handy now.

You might have to do some wire tracing to get this right. You should have:

2 Jumper cables to connect + to + and - to -
1 ground cable that goes directly to a frame connection
The rest should be positive cables to:
a 50 amp DC breaker for DC house loads and converter charging
a 100 amp DC breaker for generator starting (and levelers if equipped)
the BIM which cross connects to the chassis battery
the solar charger (if equipped) - smaller gauge cable

Hopefully this helps!

ETC/SS Retired

Thanks, Chief!

Have you come across red cables marked with black electrical tape? And, I have some of those cables with a yellow band. Most are buried in a cluster conduit but yes, tracking them down one at a time is the way to get it done.

RMC/SS retired

[DavidEM]

Usually a red cable with black electrical tape on it at intervals indicates that the cable is actually red, ie positive probably due to the factory running out of red cable. But I don't see any such markings in your last pic.

So here is how my 2021 Thor Axis was wired with a similar under the step battery box, fortunately all with the proper red and black cables:

There was a black jumper from negative of one battery to the negative of the other. One of the negative terminals had a heavy black wire that went down behind the battery and tied to a stud welded to the frame. This was the coach's ground.

There was a similar red jumper between the two positive terminals. On one of the positive terminals there was a #6 or so cable that went to a 50A breaer and then to the converter. There was also a big, maybe 1/0 red cable that went from a positive terminal up and into the engine compartment. I suspect that went to the BIM 160 battery isolation manager. There was #2 or so red cable that went from a positive terminal then to a 100 amp breaker and then to the generator starter.

Finally there was a red and black #10 cable from the 10A solar controller that had its red wire going to one of the positive terminals (through a 15A fuse). The black wire then went to a negative terminal.

In your last pic it shows a jumper between the negative terminals and a spiral wrapped heavy black cable that I'll bet goes to the chassis ground lug like mine. All others go to one or the other positive terminals.

Tracing all of them is the way to go as mentioned. You probably won't be able to trace the BIM red cable, but if it has an open circuit to ground then it is likely to be that cable. as the BIM should be an open circuit with the engine off.

David

[Neil - submariner]

Originally Posted by DavidEM

Usually a red cable with black electrical tape on it at intervals indicates that the cable is actually red, ie positive probably due to the factory running out of red cable. But I don't see any such markings in your last pic.

So here is how my 2021 Thor Axis was wired with a similar under the step battery box, fortunately all with the proper red and black cables:

There was a black jumper from negative of one battery to the negative of the other. One of the negative terminals had a heavy black wire that went down behind the battery and tied to a stud welded to the frame. This was the coach's ground.

There was a similar red jumper between the two positive terminals. On one of the positive terminals there was a #6 or so cable that went to a 50A breaer and then to the converter. There was also a big, maybe 1/0 red cable that went from a positive terminal up and into the engine compartment. I suspect that went to the BIM 160 battery isolation manager. There was #2 or so red cable that went from a positive terminal then to a 100 amp breaker and then to the generator starter.

Finally there was a red and black #10 cable from the 10A solar controller that had its red wire going to one of the positive terminals (through a 15A fuse). The black wire then went to a negative terminal.

In your last pic it shows a jumper between the negative terminals and a spiral wrapped heavy black cable that I'll bet goes to the chassis ground lug like mine. All others go to one or the other positive terminals.

Tracing all of them is the way to go as mentioned. You probably won't be able to trace the BIM red cable, but if it has an open circuit to ground then it is likely to be that cable. as the BIM should be an open circuit with the engine off.

David

David - thanks so much. I your opening paragraph you mentioned a red cable with blk tape and the cable should be viewed as red (positive). Why would they put black tape on the cable to indicate it’s red if it’s already red? What about a yellow band of tape?

Did you attach a picture?

I really appreciate your help!

Neil

[DavidEM]

Attachment 39477I misspoke (happens a lot at 76). It should read as follows:

Originally Posted by DavidEM View Post
Usually a red cable with black electrical tape on it at intervals indicates that the cable is actually black, ie negative probably due to the factory running out of black cable.

I didn't post a pic on my previous post, but I should have (76 again) so here is a pic of my original installation. It looks like Thor uses the spiral wrap on all of their cables and they are all black with red ends whether pos or negative cables. So no way to tell polarity by looking at the cable or end.

In my pic you can see the negative jumper and one big cable on the far right heading down and back to the chassis negative lug.

FWIW the second pic is after replacing the OEM G24 or G27 batteries with AGM G31s. They just fit.

David

[Neil - submariner]

Dave - I really appreciate your time and help.

On the first picture - do you have two cables along with the pos jumper on the far left?

Also, how many grounds do you have on the chassis negative lug?

You’re still a young man - I tend to forget almost everything the main squeeze tells me - and it’s been over 50 years. I arrive in San Diego, June ‘71 on a Friday. No school or duty that weekend - went downtown and met her at the bus stop on broadway. We dated and about the 10th week of the 12-week “A” school an instructor asked the class for submarine volunteers. It meant taking a 12-week self-paced Morse code school in the same building. We’ll, I could pass up another couple of months in Diego. We got married in Feb 72. I retired in Oct 92. Pray for me…��

[DavidEM]

Yes there are two pos cables on the left hand terminal plus the jumper. The other positive cable is connected to the right hand battery. I didn't have the solar wire connected when I took that pic.

I don't remember (age again) how many cables connected to the chassis ground lug. It may have been just the converter as the BIM and gen starter would pick up their grounds through the chassis frame.

David

[Neil - submariner]

Originally Posted by DavidEM

Yes there are two pos cables on the left hand terminal plus the jumper. The other positive cable is connected to the right hand battery. I didn't have the solar wire connected when I took that pic.

I don't remember (age again) how many cables connected to the chassis ground lug. It may have been just the converter as the BIM and gen starter would pick up their grounds through the chassis frame.

David

Thank you, David!!

Neil

[Neil - submariner]

David - if you get a chance can you shoot a pic of the ground lug. I have 4 wires going there, which seems extreme but that’s also my questionable area in getting this nailed down. I truly appreciate your help!

Submarines Once…”

[16ACE27]

Originally Posted by Neil - submariner

David - if you get a chance can you shoot a pic of the ground lug. I have 4 wires going there, which seems extreme but that’s also my questionable area in getting this nailed down. I truly appreciate your help!

Submarines Once…”

You have 4 wire from the batteries going there? Other items may be using the same ground lug.

Are you sure it's a ground lug and not an insulated positive distribution terminal?

[DavidEM]

I too am surprised that four wires are connected to a ground lug and I agree with Ace that it may be a pos distribution terminal.

Unfortunately I won’t be near my Axis for a few weeks, so I can’t take a pic.

David

[Neil - submariner]

David - I think you are on to something. You know, I really want our ETCS to come into radio on a Trident boat in the North Pacific to validate a flooded multi-function mast antenna but I had 5 radiomen that couldn’t stand the thought. We logged it down and it was flooded. The reason we raised that antenna was due to a loss of signal from a cut floating wire, thanks to the dive not trimming tanks. Mid-patrol - we were at PD for nearly 2 days fixing the fouled floating wire antenna mechanism from the frayed floating wire. Thank you Dive! Pride is something you can’t suppress.

I’ll let you know what I find.

Neil

[16ACE27]

Well, in my career it wouldn't be the first time RC Division fixed a piece of Radio gear, or NAV gear, or Sonar gear. Heck, we didn't go to ET "A" school and qualify in Submarines to not work as a team to solve a problem on patrol.

[Neil - submariner]

David - you nailed it. That post contained 3 cables and one from the battery. I ended up with a couple of issues I think is related to the monitor panel. No overhead lights throughout coach and head (along with fart fan). Also, no control signal to slide out controller so that’s dead. Awning works. Seems upper part of controller isn’t controlling lights and slide outs. For the lights - there are two rows of light selections. The top row has the forward, rear and head lights - and none of them work. The lower row contains the cargo, step, and awning lights and they all work. The two slide outs have touch controls also in the upper part of the display. Could be a chip/circuit board issue. That’s the only thing that applies to the lights and slide outs.

What do you think?

[16ACE27]

Originally Posted by Neil - submariner

David - you nailed it. That post contained 3 cables and one from the battery. I ended up with a couple of issues I think is related to the monitor panel. No overhead lights throughout coach and head (along with fart fan). Also, no control signal to slide out controller so that’s dead. Awning works. Seems upper part of controller isn’t controlling lights and slide outs. For the lights - there are two rows of light selections. The top row has the forward, rear and head lights - and none of them work. The lower row contains the cargo, step, and awning lights and they all work. The two slide outs have touch controls also in the upper part of the display. Could be a chip/circuit board issue. That’s the only thing that applies to the lights and slide outs.

What do you think?

I think the more I hear about these "All-in-one" control panels the less I want one. I'm sure youve checked the fuses in the power center?

BTW, no mor RMs in submarines since 1997 - they became ETs.

[DavidEM]

Do you have the BMPro system? Is that what you mean by the monitor panel. That system on my Axis is powered by two 30A DC fuses in the converter. Could one of the fuses have gotten blown which means maybe half of the system is not working?

David

[Neil - submariner]

I’m looking into the panel today and I’ll check fuses. Not sure who makes the panel. Didn’t know about that with ET’s on boats. Probably a supplemental school for communications procedures, and I wonder if they’ll copy code?

I’ll let you know what I find and thanks again.

Neil