Another dopey question

[dragon32a]

Is there a good reason for removing the split relay fuse at the battery end when not towing? My white socket on the car didn't work so went out today and found the fuse taped to the fuse holder. Popped it back in and hey presto the white socket now has power to it.

Don

 

[WatsonJohnG]

I've never found it necessary to do that.

The only reason is to prevent power getting to the circuit but as the circuit is only used when the 12S is plugged in and that is when you want to use it it seems pointless--unless I too am missing the point.

 

[Viking1]

Donald

Not to start some thick but I would be aks my self is there some thick wrong with the circuit. Is that y it was not in.

To be on the safe side I would check out or get check out. if I was you.

Mark

 

[Guest]

Agree it is never normally removed. However, one of the wires to the 12S socket is a permanently live wire that bypasses the ignition, so that may have been the reason for removal. As mentioned above it may be a good idea to have the circuits checked just in case.

 

[WatsonJohnG]

As I read it it is the fuse to the split charge relay that has been removed.

That should not affect the permanent live feed unless it has been wired with only one feed from the battery to the 12S power circuits with the relay then feeding the fridge and /or charger.

If when the fuse has been repaced it hasn't blown (which it apparentlt hasn't) then all would seem to be well.

Having it checked out should confirm this

 

[Guest]

Agree there may be a degree of confusion in this. The normal set up is a single heavy duty cable direct from the battery to the rear of the car. There is usually a main 15 amp fuse fitted just after the cable leaves the live terminal of the battery. This cable then powers the various towing aids required. These can vary depending on whether the car has bulb failure devices etc. There also can be a 10 amp fuse protecting the split relays themselves, but this is normally in the boot beside the relay unit.

A lot depends on whether the system is just for the 12S socket, or is for both 12N and 12S sockets, and of course the manufacturer. I found on my last car fitted with a '7' type relay that if the trailer was not connected then no power was seen at the sockets. That caused confusion for a while.

 

[dragon32a]

Thanks Guys,

Due to there being no power I originaly replace the white socket. As, the last time I towed the van I was going away for the week, I just left my van plugged in for three days on mains and then switched over to 12 for the journey. I have check the white socket through today and cant find any problems with it. I did however find that the same person who took the fuse out of there had also removed the fuse from the injector sensor on the car. Both fuses now replaced and both functions now working. I left the car connected to the van all day with no fires or blown fuses. I could only imagine that there was a good reason to remove the fuse. Thank you Guys for assuring me their wasnt.

Don

 

[WatsonJohnG]

Scotch Lad I do not doubt what you are saying but I always run 2 cables via fuses from the car battery to the 12S socket.

If one cable is used and the fuse blows then when the ignition is on the caravan battery will discharge via the fridge circuit.

 

[Guest]

John

I accept fully all you are stating. I was only making the point that if you buy a kit from Towsure or get Witter to do the wiring then only one feed wire is installed. I have to assume this is acceptable if the professionals are doing it.

Mind you I am now fortunate in that my S80 has the battery in the boot. Getting live feeds is now a doddle, if I need them.

I would also refer anyone who is interested in getting really serious about wiring for all types of trailers to have a look at the following. After reading it I gave my car to Witter to do the wiring as I soon realised my limitations.

http://www.rydertowing.co.uk/pdf_checklists/Practical Guide.pdf
Cheers

 

[WatsonJohnG]

Hi Scotch Lad

That was how I read your remarks too.

I remember going to an auto elecrical co and asking for a double relay only to be told that I only needed one for the fridge and charger as both wires could come off the same relay output terminal.

When I pointed out that as soon as you stopped the engine the leisure battery would discharge into the fridge etc they said well you just have to unplug the grey plug then !!!

The Hella relay kit comes/came complete with red and green wires to go back to the battery.

I only made the point because I've been there done that flattened the battery.

Regards

John