Electrical Probs, Amongst Others Forums

mooro

Hi Guys,

Been following this forum, and even more so since I bought a Fiat Ducato Autohome Bedouin this weekend. Think I got a really good deal - H reg and only 40,000 miles for £4,000. The body is in excellent condition, no rust etc. However, inevitably I have found a few problems.

First with the electrics. The Zig unit is sp-4, with dcu-3 mains unit. I was poking around the van tonight and realised that everything seems to be running off the main battery, despite the positioning of the selector switch to either aux or off. Even with the "lights" selected off on the control panel, the lights all still work. If I select aux the lights still work - however once I unplug the main battery the opposite occurs.

Now the selector switch seems to work. For example when it is set to main the lights go off (since the main battery is disconnected). When I switch to aux, the lights come on dimly and the charge indicator is red - it is green when the main battery is connected.

It seems that when the main battery is connected it "overides" the zig completely. Even with the selector set to either off or aux, it is the main batery powering everything. This power is still available even if lights are set to off on the control panel. It also seems that despite a 100mile journey home the leisure battery has not been charged. I'm presuming this is to do with the main battery "overriding" the system?

Another fault I have noted is the extractor fan doesn't come on - I'll check the fuses and also get in the roof to make sure the fan isn't caught.

Another non electrical "problem". I have a 2.5 diesel engine. It has been meticulously looked after - it has every mot since recorded and has only done 700 miles since its last, and was often serviced evey 1500 miles. The previous owner explained to me that these engines have a fuel cut out rev limiter. If I rev the engine it indeed seems that the power to the engine cuts for a few seconds - changing gear seems to restore this. When this first happened on a hill climb it was very scary. More so as my natural reaction from years driving little cabriolets was to change down for more power - I think that only changing up gears restores power. I emailed the previous owner and was reassured that this was the rev limiter kicking in, and that maybe loosening the throttle cable would be of help. I just wanted to make sure this explanation seems feasible.

The van overall is in very good condition - especially internally. I would appreciate any advice on the above issues though.

Cheers,

mooro

geraldandannie · Moderator

Hi Mooro

I just wanted to say Welcome to MotorhomeFacts - although I can't help you with any of your questions, I'm sure someone will be along tomorrow who can!

Gerald

Edit: it already is tomorrow, so hopefully someone will be along today Wink

sallytrafic · Southern Rally Co-ordinator

I'm not sure I can help but so that I can understand your post better when you say 'main' battery do you mean the 'vehicle' battery, ie the one that starts your engine?

mooro

Hi. Thank-you for the welcome.

Yes I mean vehicle when I state "main" battery.

To simplify the above post,which admittedly after a good nights sleep reads like a Harry Potter novel to a New York judge, I will paraphrase:

If the vehicle battery is connected then everything in the motorhome runs of it it appears, despite selections made on the zig control panel i.e. to aux battery or off. The other selections available on the zig seem to make no difference when the vehicle battery is connected i.e. if I select lights off on the control panel, they still work. If I do select aux battery it shows full charge - but I am sure this is actually reading the vehicle and not the leisure battery.

For example if I disconnect the vehicle battery the zig unit seems to work. If I select vehicle battery on the control panel everything goes off - since the vehicle battery is now disconnected. If I select aux battery I now get a very dim light and the low charge indicator comes on. Similarly turning the light selector on and off has the desired effect.

So it seems with the vehicle battery connected, everything is on all the time. With it off then the zig works.

As I said the vehicle has been very clearly well looked after.

Interestingly in the April edition of MMM there is an article on Talbot Express bedouins - essentially the same van. Good write up and does mention a problem they had with a relay on their second hand van. A likely culprit???

Cheers,

mooro

sallytrafic · Southern Rally Co-ordinator

Without a circuit (and I can't find one for an SP4 on the net) this is guesswork but if the voltage of your leisure battery is really low (battery knackered? charger disconnected?) perhaps there is a relay (could be solid state not electromechanical) in the zig which prevents the battery being connected.

safariboy

I cannot help very much but would certainly make sure that both batteries are giving at least 13V before trying any experiments. There is likely to be a fuse in the leisure battery circuit. This can blow if you charge a really flat battery.
I used to have a ZIG unit but it was rather different to yours and so would not help.

mooro

I've been recommended a local mobile autoelectrician who is going to come out tomorrow and take a look. Looks like I got a very good deal on the van so not going to cry if I have to spend a few hundred getting it back to A1 condition.

If any of you with expertise could have a gander at this sp-4 wiring diagram and give me any clues for the electrician I'd be grateful though:

blondy

Hi, as for your engine (problem), you must remember that diesels rev lower than petrol, especially older ones and driving is a slightly different technique. make use of its increased torque and change up much sooner.
Normally all diesels have a governor which limits revs, on older ones you could adjust this, but not wise due to engine limitations.

sallytrafic · Southern Rally Co-ordinator