James Cook Forum

I am still trying to sort out the intermittent complete power loss from the leisure batteries - power only resumes if I start the engine or hook up to 240v. Then all ok until the next loss when all readings disappear from the Central Electric Display. I suspect it is shunt related. I could just bypass the shunt as I also have a Victron Smartshunt incorporated which gives me all necessary data. But bypassing the Westfalia Shunt would mean losing it as a fusible link (100a) which protects from a catastrophe if there is a bad short. So I think I have 2 options. Either replace the shunt with another or replace it with a fast acting fuse like a 100a ANL and lose some functionality from the Central Electric Display. So 2 questions. 1. Has anyone yet found a shunt replacement that also acts as a 100 a negative fuse ? In the photo attached of the shunt ( before I tidied up the wiring!) I am assuming that the big black cable on the isolated right of the shunt is going directly to the negative pole of the batteries and that all other negative cables from loads should go the ground left side of the shunt. Thanks .

Forgot the photo!

Well, then maybe just replace the shunt - as a cheap part - and report the update.

Else go for the objective analysis from the alternator downstream to the batteries, as already suggested, and repair based on the results of that analysis: it might not be the shunt.

iCook hat geschrieben: ↑

27.07.2023 13:22

Well, then maybe just replace the shunt - as a cheap part - and report the update.

Else go for the objective analysis from the alternator downstream to the batteries, as already suggested, and repair based on the results of that analysis: it might not be the shunt.

Thanks. However I can’t find anywhere a replacement shunt for the Cook! There are lots of shunts online but none that I can find that consists of a 100a fusible link to protect against catastrophe- like the Weatfalia one. Hence why I am thinking of a fuse.

Hi!
A replacement part for the shunt has been discussed here:

https://forum.james-cook-freunde.de/vie ... unt#p58964:

ATTENTION! BEWARE!
The second last entry states that the part discussed does not seem to solve the problem.

Else: contact Manfred Ermel https://www.ermel-freizeitmobile.de/ for the shunt as a replacement part.

Cheers mate,

Wolf

I guess that even the Westfalia shunt is not designed to act as a fuse. However, the specification of the shunt is 100A/200mV so that the shunt is actually designed to Route at least up to 100A.

The problems discussed in the linked thread might be minor for you as you already have a smart shunt for precise information.

Actually the shunt in your photo does not look like it was burned to me. Maybe it is not related to the shunt. Did you check the shunt by measuring the voltage or current or resistance between the both shunt connection bolts?


Best regards,
Matthias

HerrmannOnTour hat geschrieben: ↑

27.07.2023 17:57

I guess that even the Westfalia shunt is not designed to act as a fuse. However, the specification of the shunt is 100A/200mV so that the shunt is actually designed to Route at least up to 100A.

The problems discussed in the linked thread might be minor for you as you already have a smart shunt for precise information.

Actually the shunt in your photo does not look like it was burned to me. Maybe it is not related to the shunt. Did you check the shunt by measuring the voltage or current or resistance between the both shunt connection bolts?


Best regards,
Matthias

Thanks Matthias. I agree that the Shunt looks ok but I can’t think of another reason for the power losses. At the moment with minimal load it is working ok. I’m not sure how to test it with a
Multimeter. I suppose I could put as many appliances on as possible and then check using ground at the batteries,then the isolated end of the shunt and then the ground end? Otherwise as an experiment I could bypass it with a 100mega fuse ( that I have spare) and see if that improves things.
Finally, is my assumption right in the photo that the thick black cable on the right of the shunt( which has brown wires taped to it) should go to the negative terminal of batteries? I ask because in my set up I can’t trace it to the batteries- does it go somewhere else as a ground? Thanks. Adrian

Hi,

hab etwas Probleme mit dem Shunt oder der Zentraleinheit. Die Volt Anzeige ist sehr schwankend und geht runter auf 10,5V, bis der Kühlschrank aussteigt. Kabelbruch der Meßleitung ist ausgeschlossen.

Kann mir jemand die Mercedes Ersatzteilnummer vom Shunt verraten?
Müsste nen neuen bestellen, wenn's ihn denn noch gibt.

Vielen Dank!

Grüße,
Arne

Arne, greetings from the U.K. I recently obtained one from Manfred Ermel. Adrian.