Water Pump - Low Voltage

[Washburn]

I am having an issue with my water pump. I have scoured the threads here and took almost all of the advice I found to troubleshoot and resolve my issue but no luck.
Quick background:
2005 Cali - 2.5 TDI, 197000km
Vehicle was imported from France into Canada back in 2021.

I have upgraded the leisure batteries to a pair of 100Ah Renogy Lithium Iron Phosphate batteries. I have had no issues with the my electrical system (including the water pump) either before or after the upgrade. After month long trip around British Columbia where the sink pump was used a couple times day (always with the engine off and no shore power connected), we arrived home and after a day getting settled we went back out to the van to empty out the last of the gear and give it a good clean. It was at this point that we noticed the sink pump not working. Once the van was cleaned out I took at look at the pump and tested the power going to the pump by unplugging the wire connections going to the pump just outside of the water tank. Voltage tested at 11.6 volts. At first I thought that was probably fine, even thought the leisure batteries had nearly a full charge (showing 98.6% on the Renogy bluetooth app) and 13.4 and 13.3 volts on batteries 1 and 2 respectively. So I assumed the pump went bad and placed an order for an OEM replacement. When I got the new pump (a couple months later) and plugged it in and, as you all can imagine,…nothing - still didn’t work. Ok, quick test by connecting the pump to direct to the battery and it worked fine (as did the old one - probably to no one’s surprise reading this here). So the next thought was some kind of issue with the switch causing resistance and dragging the voltage down to 11.6. So I connected my multi-meter to the line before the switch (by unplugging the switch harness under the sink) - still 11.6 volts. Then I tried testing with the engine running - still 11.6 volts.

Obviously there is a lot of discussion about a bad earth connection in these models, but NONE of the symptoms of this (lights flickering, heater not starting, etc with the engine off and no shore power connected) were happening in my van. Everything else electrical is performing well - i.e. the heater doesn’t hesitate even bit when starting up even with the fridge on and the lights don’t flicker at all.

I know there is a 5 amp fuse under the left (in my case, drivers) seat and my next step is to test the load side of the fuse connection and see what voltage I get there and of course I haven’t ruled out a bad earth connection as well.

What does the group here think my next steps should be or what other possible cause might be at play here? I feel like I am just missing something obvious.

Thanks to everyone who managed to read all the way through this post.

 

[Resfeber]

I am having an issue with my water pump. I have scoured the threads here and took almost all of the advice I found to troubleshoot and resolve my issue but no luck.
Quick background:
2005 Cali - 2.5 TDI, 197000km
Vehicle was imported from France into Canada back in 2021.

I have upgraded the leisure batteries to a pair of 100Ah Renogy Lithium Iron Phosphate batteries. I have had no issues with the my electrical system (including the water pump) either before or after the upgrade. After month long trip around British Columbia where the sink pump was used a couple times day (always with the engine off and no shore power connected), we arrived home and after a day getting settled we went back out to the van to empty out the last of the gear and give it a good clean. It was at this point that we noticed the sink pump not working. Once the van was cleaned out I took at look at the pump and tested the power going to the pump by unplugging the wire connections going to the pump just outside of the water tank. Voltage tested at 11.6 volts. At first I thought that was probably fine, even thought the leisure batteries had nearly a full charge (showing 98.6% on the Renogy bluetooth app) and 13.4 and 13.3 volts on batteries 1 and 2 respectively. So I assumed the pump went bad and placed an order for an OEM replacement. When I got the new pump (a couple months later) and plugged it in and, as you all can imagine,…nothing - still didn’t work. Ok, quick test by connecting the pump to direct to the battery and it worked fine (as did the old one - probably to no one’s surprise reading this here). So the next thought was some kind of issue with the switch causing resistance and dragging the voltage down to 11.6. So I connected my multi-meter to the line before the switch (by unplugging the switch harness under the sink) - still 11.6 volts. Then I tried testing with the engine running - still 11.6 volts.

Obviously there is a lot of discussion about a bad earth connection in these models, but NONE of the symptoms of this (lights flickering, heater not starting, etc with the engine off and no shore power connected) were happening in my van. Everything else electrical is performing well - i.e. the heater doesn’t hesitate even bit when starting up even with the fridge on and the lights don’t flicker at all.

I know there is a 5 amp fuse under the left (in my case, drivers) seat and my next step is to test the load side of the fuse connection and see what voltage I get there and of course I haven’t ruled out a bad earth connection as well.

What does the group here think my next steps should be or what other possible cause might be at play here? I feel like I am just missing something obvious.

Thanks to everyone who managed to read all the way through this post.

You could spend a long time trying to trace this from fuse to connector before tap micro switch or use the degraded voltage from the switch to power a relay and take a good supply to the relay to power the pump.

This comprehensive post covers most tap electrical problems and describes the relay improvement which is where my copied link starts

Post in thread 'How to Fix Kitchen Tap and Water Pump Problem and solution.'

How to Fix Kitchen Tap and Water Pump Problem and solution.

Perhaps both ways work?

vwcaliforniaclub.com

 

[WelshGas]

I am having an issue with my water pump. I have scoured the threads here and took almost all of the advice I found to troubleshoot and resolve my issue but no luck.
Quick background:
2005 Cali - 2.5 TDI, 197000km
Vehicle was imported from France into Canada back in 2021.

I have upgraded the leisure batteries to a pair of 100Ah Renogy Lithium Iron Phosphate batteries. I have had no issues with the my electrical system (including the water pump) either before or after the upgrade. After month long trip around British Columbia where the sink pump was used a couple times day (always with the engine off and no shore power connected), we arrived home and after a day getting settled we went back out to the van to empty out the last of the gear and give it a good clean. It was at this point that we noticed the sink pump not working. Once the van was cleaned out I took at look at the pump and tested the power going to the pump by unplugging the wire connections going to the pump just outside of the water tank. Voltage tested at 11.6 volts. At first I thought that was probably fine, even thought the leisure batteries had nearly a full charge (showing 98.6% on the Renogy bluetooth app) and 13.4 and 13.3 volts on batteries 1 and 2 respectively. So I assumed the pump went bad and placed an order for an OEM replacement. When I got the new pump (a couple months later) and plugged it in and, as you all can imagine,…nothing - still didn’t work. Ok, quick test by connecting the pump to direct to the battery and it worked fine (as did the old one - probably to no one’s surprise reading this here). So the next thought was some kind of issue with the switch causing resistance and dragging the voltage down to 11.6. So I connected my multi-meter to the line before the switch (by unplugging the switch harness under the sink) - still 11.6 volts. Then I tried testing with the engine running - still 11.6 volts.

Obviously there is a lot of discussion about a bad earth connection in these models, but NONE of the symptoms of this (lights flickering, heater not starting, etc with the engine off and no shore power connected) were happening in my van. Everything else electrical is performing well - i.e. the heater doesn’t hesitate even bit when starting up even with the fridge on and the lights don’t flicker at all.

I know there is a 5 amp fuse under the left (in my case, drivers) seat and my next step is to test the load side of the fuse connection and see what voltage I get there and of course I haven’t ruled out a bad earth connection as well.

What does the group here think my next steps should be or what other possible cause might be at play here? I feel like I am just missing something obvious.

Thanks to everyone who managed to read all the way through this post.

Personally I would check the power input to the water pump fuse.
if that is OK then check the multi connector under the kitchen. See enclosed California Supplement.
if you have a high resistance connection this could cause problems if not attended to.

 

[sidepod]

As with any basic volt drop test, check at every junction along the path till you find the drop. I’d be amazed if the pump failed to run at 11.6 v?

 

[Washburn]

You could spend a long time trying to trace this from fuse to connector before tap micro switch or use the degraded voltage from the switch to power a relay and take a good supply to the relay to power the pump.

This comprehensive post covers most tap electrical problems and describes the relay improvement which is where my copied link starts

Post in thread 'How to Fix Kitchen Tap and Water Pump Problem and solution.'

How to Fix Kitchen Tap and Water Pump Problem and solution.

Perhaps both ways work?

vwcaliforniaclub.com

Thanks Resfeber. I did see this post about the relay and thought, "Ok that's a brute force solution I may just have to do", and still ultimately may, but would also like to see if I can understand/identify the source of the issue. (FYI, this van has been, at times, a nightmare to get back to full working order - has almost certainly been in an serious accident at one point in its life - probably the worst due diligence I have ever done on a purchase).

But thanks for posting the link. I really love the quick response from the community.

 

[Washburn]

Personally I would check the power input to the water pump fuse.
if that is OK then check the multi connector under the kitchen. See enclosed California Supplement.
if you have a high resistance connection this could cause problems if not attended to.

WelshGas, thanks for the Supplement. Not sure why I hadn't found it on this site before. My van was completely barren of any documents (even the jack and toolkit were missing), so this will be very helpful.

Regarding the fuse, yes, as I mentioned, that was my next step. Just wanted to see what others had to say before removing the seat (I know - I really don't have to actually remove the seat but expect that if the power input still shows 11.6 then I'll be tracing it farther into the harness & connections there anyways).

Thank again for the quick reply. This forum (and my now close friend and other Victoria BC-based Cali owner, @Doug Curran) have been invaluable.

 

[Washburn]

As with any basic volt drop test, check at every junction along the path till you find the drop. I’d be amazed if the pump failed to run at 11.6 v?

I agree. That's why when I first tested the connection and saw 11.6 volts I made the immediate (and incorrect) assumption that the pump was bad. I guess, as other threads have mentioned, the initial amperage draw can overload the weaker points in the circuit.