Electrical advice for new owner

[SimonB73]

Hi

Me and my wife have just bought a very cheap and old van. I’ve managed to get everything working except the water system. I think maybe the pump is broken but i thought I’d ask on here because I’ve never had a caravan before and I’m guessing a lot of the time.

I did some testing after reading other posts on here. It may or may not help.

I switched the control panel to caravan and turned the pump switch on (Without the pump connected).

I checked the voltage at the battery and it’s poor – 11.58 or something. So i think i need a new leisure battery?

Would that stop the pump from working?

I also checked the voltage at the terminals on the pressure switch behind the pump socket and got around 9.

Then i checked the contacts in the pump plug socket and the voltage seemed to cycle through a range of values from 9 to 0.

It’s a bit awkward getting my multimeter in there so i was wondering if i was just not getting good contact (It was dark too so couldn’t see very well) or if that is what the pump system does?

I was thinking i might get some crocodile clips and connect the pump directly to the battery? Think i might have read about testing it that way on another post on this forum. I also read somewhere that if you take the terminals from the back of the pump socket and join them together either the pump will work or the 5 amp fuse will blow. Is that true? Because it’s easier than faffing about with crocodile clips.

One more question. If the pump is broken is it easy to attach a new pump to the existing socket and tubing?

Would really appreciate some advice on this as my wife is desperate to get out and do some camping. We’re only back from three weeks camping in France and Spain but now we have a caravan to play with!

Cheers

Simon

 

[Damian]

As far as the battery is concerned, at 11.58v it is flat and would not power a pump, or anything else 12v.
The battery should be charged by an on board charger which should give you around 13.8v at the battery terminals if in fact a charger is fitted and working, if there is not one, you need to sort out getting one.

The battery needs testing to see if it is any good and will hold charge

You do not want to go shorting wires together, you will cause more damage than solve problems.
As it is an old van the pump terminals may be badly corroded and need a clean, or possibly a new pump connection if they are too bad.

Depending on what pump and connection you have it is reasonably easy to change the pump but you would be better getting a complete new pump assembly.

If you are not happy with electrics it s better to get someone who does know about them to check the system as a 12v short circuit can easily cause massive problems and fire.

 

[Jules_ht]

Chuck your car battery in there and test it with that.

 

[chrisn7]

If your battery has been at that voltage level for any length of time, its Kaput. Those low voltages where you have been testing suggest you have other problems in the cable run, which will almost certainly be corrosion related. Apart from very long cable runs, voltages end to end of an uninterrupted cable should be just about the same. Spade terminals are often used, and these are readily available along with matching insulation sleeves for live connections. If your practical skills include soldering, do this on replacement terminals, rather than crimping for long term reliability.
I assume you are referring to the submersible pump in your Aquaroll - in which case it is possible to replace this. The cables to it are reasonable heavy duty, so you will need a decent wattage soldering iron (no 25 watt toys please). Give the filter end a good swill round first though in case there is a blockage. It could well be duff though, they can last about 30 mins if left on accidentally with no water left to pump - I know!

 

[SimonB73]

Thanks for the replies folks.

I'll try cleaning the contacts and hook the van up to the mains again.

The battery does charge but not fully. It'll run the lights for a few hours once the hook up is disconnected but if left overnight it goes flat.

Should i be replacing the battery before buying a new pump?

Also, would it be a valid test of the pump to get my jump leads out of the car and hook it up to that battery?

 

[DrZhivago]

Should i be replacing the battery before buying a new pump?

Yes. Sounds like the battery is kaput but there might be nothing wrong with the pump. You don't know yet.

Also, would it be a valid test of the pump to get my jump leads out of the car and hook it up to that battery?

No. To test the pump itself (as opposed to its loom connections, which would be a different matter and test), disconnect it from the caravan electrics entirely and connect it directly to your car battery (or your new van battery) instead, and see if it runs. Dont use jump leads because if you do accidentally short them they will pass a huge and dangerous current. Use something like 5 amp rated wire with crocodile clips as they will be self-limiting if there is a short.

But if you first replace the battery and the pump then runs well, you won't need to test the pump specially.

 

[SimonB73]

Hi

Got a battery but still no water so ordered a pump and now it works fine.

Was actually a bit of excitement when the water started coming out of the taps!

Seems like everything works now. Even the water heater. Hot water coming out of the taps was even more exciting.

So thanks for all your responses. We're embarking on our maiden voyage tomorrow (weekend in Newcastle) and really looking forward to it.

All i need to do now is post a couple of basic operation questions and watch a video on how to erect the awning. The awning is especially daunting. I've checked through the contents but since i've never set one up before i don't even know if all the necessary bits are there. Maybe a big glass of beer will make it easier....

So thanks again folks.

 

[weijing3333]

Yes, I think you need a
Moderator Note:
External link to solar energy company removed.
User banned.

 

[M5WJF]

Automotive and Deep-Cycle Batteries are fully charged at 12.7v, and fully discharged at 11.7v

You need 13.2v to keep a continuous preservation charge, and chargers should charge the battery between 13.2-14.4v, as above 14.4v the battery starts gassing, producing Hydrogen, so if you have a severe overcharge, and/or poor ventilation, an internal spark could ignite the explosive mixture.

Generally with an Automotive Battery, to prolong it life, it really shouldn't be allowed to drop below 50% charge, or 12.1v before being charged again.

Also for a Deep-Cycle Leisure Battery, it is designed to deliver its best performance between 75%-45% charged, so aim for the same 12.1v no load (approx 10.9v under 25A load), and then charge the battery to 12.7v, until the charger tells you its charged. Going below 45% will generally reduce the life of the battery, going above 75% will be less efficient for some equipment, but not something you can control.

If anyone says they have got a higher voltage at the terminal during charging this is down to loading the terminals with electrons, and it is transient and gone within a second of current being drawn, 12.7v is fully charged, older Batteries will give a lower voltage at maximum charged because they are deteriorating chemically, producing an increasing internal resistance over time. You can observe this 'loading' by using a meter on the battery terminals, you'll see the voltage drop even with the insignificant load from the meter, until it get to around 12.7v (on a new battery).

Under load the voltage will drop, you will only notice the state of charge by removing the load and measuring the voltage at the terminals.

If you put a 25 Amp load on the battery, and the voltage read 10.5v at the terminals while its under load, then the battery is flat.

I agree with all the comments on corroded terminals at your pump.