Scubawise
Senior Member
Again not sure i wire old battery a to batt chassis on bim 225
That breaker is for the feed to the Thor/Bussman fusebox under the hood. There is no circuit breaker between the BIM and either battery/bank.There should be a 100 amp DC breaker under the hood as well. Trip it and see which side goes to 0. That's the chassis side.
When I put the multimeter on both Batt A & batt B shows 12.8 votts. Even red black multimeter reversed and reading 12.8.
That would work if the old one was wired correctly. Probably not...Your old Bim and your new Bim are built exactly the same externally. Mount the cables where they came off of the old one onto those positions on the new one.
You're overthinking this...Again not sure i wire old battery a to batt chassis on bim 225
I am overthinking. BUT. I turned my multimeter to 20amp. The coach batteries are physically removed. BUT. I must not understand something. When I put the multimeter black probe on batt A & red on bat b ...it reads 12.8 & same in reverse.You're overthinking this...The Li-BIM 225 terminals are clearly marked... TRUST that! Ignore how your previous BIM was wired, considering all the banter about being wired backwards, etc.
Since you have your house batteries disconnected, but your chassis battery is STILL connected... WITH THE CABLES DISCONNECTED FROM THE Li-BIM 225, check voltage on the cable coming from the chassis battery... 12+ volts, correct?
Now check voltage on the cable coming from your house battery area... 0 volts, correct?
If you DEFINITELY have house batteries disconnected, the cable with 12 volts (not 0 volts) HAS to be the chassis battery cable... and connects to the "Batt Chassis" terminal.
Connect the cables to the appropriate labeled terminals...
View attachment 1320443
Why are you measuring that? I think Duck stated that when you connect the chassis battery to the Li-BIM 225 (with no house battery connected) the relay in the BIM will close... trying to charge a non-existent house battery. That's where you're getting the voltage read across those terminals.I am overthinking. BUT. I turned my multimeter to 20amp. The coach batteries are physically removed. BUT. I must not understand something. When I put the multimeter black probe on batt A & red on bat b ...it reads 12.8 & same in reverse.
You're right. That breaker supplies the Thor chassis loads.If the BIM is used to 'jump start' the chassis battery from the coach battery, would there still be a breaker on that line? I would think the starter draws more than a 100 amps, no?
Remove one of them.I am overthinking. BUT. I turned my multimeter to 20amp. The coach batteries are physically removed. BUT. I must not understand something. When I put the multimeter black probe on batt A & red on bat b ...it reads 12.8 & same in reverse.
Yes. Thx I see that logic nowWhy are you measuring that? I think Duck stated that when you connect the chassis battery to the Li-BIM 225 (with no house battery connected) the relay in the BIM will close... trying to charge a non-existent house battery. That's where you're getting the voltage read across those terminals.
That voltage is meaningless at this point. But when you get your house batteries installed and connected to the Li-BIM 225, it will monitor both battery banks and connect them as necessary.![]()
Great. That bim 160 screw configuration is a pain in the ASX.Remove one of them.
The chassis battery lead will still have voltage on it.
The house battery lead will not.
0-20 volts DC, right, not amps? My meters do measure amps so just checkingI am overthinking. BUT. I turned my multimeter to 20amp. The coach batteries are physically removed. BUT. I must not understand something. When I put the multimeter black probe on batt A & red on bat b ...it reads 12.8 & same in reverse.
Be sure you have a good ground for the black lead or it will mess with you when reading voltage, and as noted if your reversed then the negative voltageGreat. That bim 160 screw configuration is a pain in the ASX.
Labeled wires covered ends removed all wires.
Removed bim 160.
Installed new li 225 without wires.
I guess I could now test independently the Removed bat A & BAT B to see which is hot?
The multimeter has black red probes.
Can I put the black & red probe on each time see voltage?
This sounds like multimeter 101.Great. That bim 160 screw configuration is a pain in the ASX.
Labeled wires covered ends removed all wires.
Removed bim 160.
Installed new li 225 without wires.
I guess I could now test independently the Removed bat A & BAT B to see which is hot?
The multimeter has black red probes.
Can I put the black & red probe on each one to see voltage?
Yes sorry did 20V on multimeter.It doesn't matter black or red.
It will read
12.8
Or
-12.8
It doesn't matter for what you're doing.
And
You dont set the meter on amps.
You set it on DC volts.
If a selection the dial is 20v, use that.
Yes thx that was my problemThis sounds like multimeter 101.
One lead goes to the metal chassis - usually the black lead.
The red lead goes to where you are trying to measure the voltage.
If you reverse the leads the voltage will be reversed.
You DO NOT measure from one cable to the other.