Bad BIM, rolling anyway

[CRPerle]

So, as far as I can gather, our house and chassis batteries are always connected. The BIM160 appears to not be functioning.

The house batteries are brand new, grp 31, 110 Ah each.

We started our trip today with no end point planned.
We don't have any boondocking planned at the moment, but what risk are we taking? What bad things can happen besides accidentally running down the chassis battery? (We have a jumpstarter).

This is a Thor Hurricane 34J. I have a BIM160 on order, but it will be about 2 weeks before I can install it.

TIA

 

[DavidEM]

What you can do to keep from running down your chassis batteries is to disconnect the chassis battery cable from the BIM and wrap the end with electricians tape to keep it from touching ground. Make sure that it is really the chassis battery cable as Thor often wires the backwards. Come to think of it, it really doesn’t matter, just disconnect one side.

This way the chassis battery will be independent of the house battery.

The Precision Circuits BIM 160 rarely fails, but it does seem that yours did.

David

 

[16ACE27]

What David said. There is absolutely no reason to keep the chassis and house batteries tied together and a few reasons not to.

 

[ducksface]

https://www.amazon.com/gp/aw/d/B004HGTXUQ?psc=1&ref=ppx_pop_mob_b_asin_image

https://www.amazon.com/gp/aw/d/B09W5SFK6L?psc=1&ref=ppx_pop_mob_b_asin_image

As long as you're messing with the bim I THINK these lugs could be attached right to it.

 

[SGilbert]

I installed this:
https://www.amazon.com/gp/product/B0C1NKCLTR/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

 

[CRPerle]

What you can do to keep from running down your chassis batteries is to disconnect the chassis battery cable from the BIM and wrap the end with electricians tape to keep it from touching ground. Make sure that it is really the chassis battery cable as Thor often wires the backwards. Come to think of it, it really doesn’t matter, just disconnect one side.

This way the chassis battery will be independent of the house battery.

The Precision Circuits BIM 160 rarely fails, but it does seem that yours did.

David

Thanks. I actually bought quick disconnects at the negative terminal for this purpose. But I haven't installed them. I might if it comes to that, BUT no concerns about overworking the alternator overcharging the house batteries while driving? Doesn't the BIM decide when to charge the house batteries while driving?

 

[ducksface]

I installed this:
https://www.amazon.com/gp/product/B0C1NKCLTR/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

The cable alone(this is sad. Wire is stupid right now) is worth the cost
And
I had to build my own mount.


Buy this.

 

[CRPerle]

Is this just to make jump starting easier?

This is what I bought as quick disconnect at the negative terminal...

 

[CRPerle]

It might be wired wrong, I guess.
So,no need to worry about damaging anything? Batteries? Alternator?

 

[ducksface]

Yes.
It makes it so you don't have to get involved with the chassis or coach battery.
Mine hooks directly to the chassis battery with 1/0 cable.
I've moved both my chassis battery and coach bank of batteries to an easily accessed area where i can get to the terminals if needed. The under hood lugs allow me to jump others if needed, and far worst case, someone can jump me from the front as is normal.

Just something to do since you have to do 90% of the labor anyway to replace that bim.

And
While you're doing that, buy the lithium bim.
You'll be putting them in sooner or later.

 

[16ACE27]

Thanks. I actually bought quick disconnects at the negative terminal for this purpose. But I haven't installed them. I might if it comes to that, BUT no concerns about overworking the alternator overcharging the house batteries while driving? Doesn't the BIM decide when to charge the house batteries while driving?

Only if it is working correctly.

 

[CRPerle]

Is the idea here a like a manual BIM?

I do want the house batteries charging while underway...

Excuse my naivete here, this is our first RV and board have actual switches that actually physically isolate batteries!

 

[CRPerle]

Thanks. The Hurricane has a dedicated battery compartment and thankfully, the chassis battery is easy to get to.

Of course, the BIM hides behind the 2 house batteries!

 

[CRPerle]

Boats, not board!

 

[CRPerle]

Well, they seem to be getting charged, that's for sure. I think I have the opposite issue. They are always on the same circuit, not always on separate circuits...

 

[Bob Nodine]

Well, they seem to be getting charged, that's for sure. I think I have the opposite issue. They are always on the same circuit, not always on separate circuits...

Did you check to see if the two battery systems were still connected when the engine is off? That would be the one to worry about as it could drain down your chassis battery while you are parked.

The BIM contactor should be a normally open contactor so unless the contacts are welded together (which I doubt) the BIM may be wired incorrectly or the emergency start switch has the contactor permanently energized.

 

[Judge64]

So, as far as I can gather, our house and chassis batteries are always connected. The BIM160 appears to not be functioning.

The house batteries are brand new, grp 31, 110 Ah each.

We started our trip today with no end point planned.
We don't have any boondocking planned at the moment, but what risk are we taking? What bad things can happen besides accidentally running down the chassis battery? (We have a jumpstarter).

This is a Thor Hurricane 34J. I have a BIM160 on order, but it will be about 2 weeks before I can install it.

TIA

What year is your Hurricane?

Just be aware that the BIM160 was also used on the Omni / Magnitude. I purchased on the first SV34 and found that Thor had wires most of the BIM160's backwards in the Omni / Magnitudes for several model years.

This caused all kinds of 12V issues including slide operation, chassis and house battery voltage reporting and charging.

It might not be you issue but you might want to search for a couple of my posts about how the BIM should be wired and how to test to see if it is wired correctly if it isn't easy to trace the wiring.


Here is just one of the threads about it and there are severak others......

https://www.thorforums.com/forums/f10/chassis-coach-battery-voltages-25455.html

 

[CRPerle]

Thanks. It's a 2017.
I did your test last time I had access to shore power, running house versus chassis systems (headlights).
It indicated house/chassis were not separated. House batteries were bad, so I installed new house batteries (chassis is from this year, before I bought the rig, possibly an indicator of a problem, I guess) and will run that test again in a few days at a campground, just to be sure.
Another indicator is that they always read the same voltage, at rest and when charging. I have a BIM 160 wiring diagram, and I'll double check that at the next chance.
I guess it's possible the BIM160 is fine and and the "emergency start" circuit is at fault?

I do get code 9s on the slide/bunk controllers a fair amount. Reset and go works fine though.

Upon inspection, the controller was found to be bad. I had it replaced and something blew the 30 amp fuses. Replaced the fuses and seems to work fine. Technician said other things besides reverse polarity can blow the fuses. I did find a loose connection at the 100amp fuse in the battery box that maybe spiked the voltage? Everything is tight now.

No boondocking planned just yet, I'm wondering if I should think harder about taking the rig in to a shop...

Thanks

 

[Judge64]

Thanks. It's a 2017.
I did your test last time I had access to shore power, running house versus chassis systems (headlights).
It indicated house/chassis were not separated. House batteries were bad, so I installed new house batteries (chassis is from this year, before I bought the rig, possibly an indicator of a problem, I guess) and will run that test again in a few days at a campground, just to be sure.
Another indicator is that they always read the same voltage, at rest and when charging. I have a BIM 160 wiring diagram, and I'll double check that at the next chance.
I guess it's possible the BIM160 is fine and and the "emergency start" circuit is at fault?

I do get code 9s on the slide/bunk controllers a fair amount. Reset and go works fine though.

Upon inspection, the controller was found to be bad. I had it replaced and something blew the 30 amp fuses. Replaced the fuses and seems to work fine. Technician said other things besides reverse polarity can blow the fuses. I did find a loose connection at the 100amp fuse in the battery box that maybe spiked the voltage? Everything is tight now.

No boondocking planned just yet, I'm wondering if I should think harder about taking the rig in to a shop...

Thanks

One othet thing to check is whether thr Emergency Start momentary switch is stuck on. The Switch is meant to temporarily connect the chassis and house batteries. If it is stuck on, the relay will keep the batteries tied together.

 

[CRPerle]

Yes, someone else mentioned that.
How do I test that independently of the BIM?
If either one is closing the circuit an amp spiked upon ignition at the house side would be evident, right?
I'd have to disconnect the house cables from the BIM first?
Is there a better way?

By the way, this is all very much appreciated!