Anyone know what this loose wire is near my PDC?

[duckdave]

I just found a Service Manual covering my 06 Sprinter by entering the search terms "T1N Service Manual". Seems there were a couple that came right up to choose from. I downloaded one that's over 1400 pages as a pdf with links to pages from the Table of Contents and from the Index.

This could come in handy!

LB_3: It describes the procedure you just mentioned. Thanks!

[duckdave]

I finally got the chance to look for my BIM under the seat. It turned out to be much easier than I imagined. I sure am glad I looked for the lever to pop off the seat bottom. MUCH easier than removing the entire seat.

First I removed the worn out seat covers. This revealed everything I was unaware of before. There are 4 red adjustment levers that I could not see clearly with the seat covers in place. One of them, the front one, actuates the lever in question—and sure enough, the seat bottom slides forward and off no problem. Now, everything is visible by just moving the seat position back and forth. Two more screws and the vented electrical cover is off.

And just as predicted by LB_3, there is the BIM, with the same part number shown in his picture. A heavy red cable and another wire is connected to the BIM. What is the other wire? I assumed it was to ground, but I might need to follow it out a bit. I assume the BIM is a relay of sorts that switches current between the red battery cable and the other wire. It doesn't make sense it would be switched to ground.

I checked the voltage between battery cable and other cable—zero V. I checked continuity between the loose wire near my battery and the cable going to the BIM—just a fraction of an ohm. My suspicions are that the loose cable near the chassis battery is the one that goes to the BIM.

I haven't had time to think this one through yet. I'm not sure what is the function of the BIM. Perhaps there are other wires that go to the BIM besides the two cables I have noticed so far. I will have to study this more.

I'll need to understand more before I just hook up the unconnected cable. The "fusable link" (I guess that's what it called) is missing on the battery side, and I don't know what size it needs to be. I might assume it's disconnected because of some problem (blows fuse, BIM doesn't work, short somewhere else?) Does this have anything to do with my coach battery? I don't want any smoke to escape!

Thanks to all who have been so helpful. It's a work in progress.

[LB_3]

The rear lounge models in 2007 had a battery box under the floor in the rear of the van instead of under the passenger seat. This required Airstream to mount the spare tire on the back door. We have a mid bath rear sleeper so I’m not sure exactly how the lounge batteries get integrated.

The BIM is intended to isolate the house loads from the chassis battery so that running down your house battery doesn’t leave you stranded somewhere. When the engine is running, the BIM should close the circuit allowing the alternator to charge the house battery (slowly). The loose wire at the buss bar under the hood should connect to one side of the BIM. The other side of the relay should eventually be connected to the battery.

In our van there was a short jumper connecting the BIM to a terminal post. The terminal post looked like it was installed by Airstream. From the terminal post one wire went to the Starter motor on the generator and the other wire went to a cheap thermal breaker and from there the cable went through a tunnel to the passenger seat.

If your battery is in the rear, the cable probably runs under the van to the rear.

[InterBlog]

Originally Posted by duckdave

I just found a Service Manual covering my 06 Sprinter by entering the search terms "T1N Service Manual". Seems there were a couple that came right up to choose from. I downloaded one that's over 1400 pages as a pdf with links to pages from the Table of Contents and from the Index.
...

These older reference materials keep migrating around the internet as various sites cease hosting and return 404s during searches.

Here is one of the active current sites.

[LB_3]

Originally Posted by LB_3

The rear lounge models in 2007 had a battery box under the floor in the rear of the van instead of under the passenger seat. This required Airstream to mount the spare tire on the back door. We have a mid bath rear sleeper so I’m not sure exactly how the lounge batteries get integrated.

The BIM is intended to isolate the house loads from the chassis battery so that running down your house battery doesn’t leave you stranded somewhere. When the engine is running, the BIM should close the circuit allowing the alternator to charge the house battery (slowly). The loose wire at the buss bar under the hood should connect to one side of the BIM. The other side of the relay should eventually be connected to the house battery.

In our van there was a short jumper connecting the BIM to a terminal post. The terminal post looked like it was installed by Airstream. From the terminal post one wire went to the Starter motor on the generator and the other wire went to a cheap thermal breaker and from there the cable went through a tunnel to the battery under the passenger seat.

If your battery is in the rear, the cable probably runs under the van to the rear.

fime (fixed it for me)

I missed my edit window.

[duckdave]

InterBlog,
That vast collection of T1N Sprinter documentation should be very useful.

LB_3,
OK, I think I'm starting to grasp what's going on. So the way mine is now, I should NOT be able to detect 12V on the wire coming from the chassis PDC (power distribution center), because, of course, it's disconnected. BUT, I should be able to detect 12V on the other side, if it is still connected to the coach (house) battery...right?

I want to move toward reconnecting everything, but worried that I don't know the reasons it's been disabled. On the PDC side, the cable is disconnected, AND the fuse (I believe it can be called "Fusible Link") is missing. What size fuse is needed. And what are likely scenarios for it to be disconnected? Perhaps if the BIM was not working properly, causing batteries to be discharged, or overcharged?

This would be a good time to get that Tone Generator/Wire Tracer LB_3 recommended. Can anyone out there recommend a brand/model that works for you?

Thanks all!

[LB_3]

Under the hood it takes an actual fuse and not fusible links:

Here is an example: http://europarts-sd.com/fuse-100amp2002-2009-1.asp

I would think 80A would be enough.