# Electrics help needed



## 104650 (May 21, 2007)

Hi everyone - kind of new to all this and need a wee bit of help with the electrics. Firstly I have a Plug In Systems Zag type box - markled PMS 3H - sadly no instructions on how it should all be wired. The PMS doesn't seem to work on the van battery - don't suppose anyone has a installation manual for one of these PMS 3H boxes? Next to it is a 6 pin relay - and two wires are not connected. One is an earth wire attached to the van itself and the other is a wire coming off the relay.

The relay is wired as such

Pin 1 - the unconnected wire
Pin 2 - has a wire which seems to have a joint feed from leisure battery and connected also into the +ve socket in the PMS 3H
Pin 3 - not used
Pin 4 - wire again has a double feed - from the Van battery and also to the car +ve connection in the PMS
Pin 5 - connected to the DC -ve connectors on the PMS
Pin 6 - looks like a direct feed taken from the engines alternator

Now I wonder where the mystery cable goes? Could any of this have something to do with the fridge? 

Any help greatly appreciated - its so annoying as it all worked until a friend removed the cable and now hasn't a clue where it goes back - (OK I did it LOL)


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## hbspc (May 1, 2005)

*pms*

i did have some wiring diagrams for the various pms systems, when i am at work tomorrow i will have a look


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## hbspc (May 1, 2005)

*check this out*

http://www.motorhomefacts.com/downloads-file-131.html#dl


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## 104650 (May 21, 2007)

Thanks - don't seem to be able to get onto that page - do I have to subscribe or something - new to this site?


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## geraldandannie (Jun 4, 2006)

I'm afraid the downloads section is out of bounds to you as a non-subscribed member 

Here's some other advantages to subscribing :wink:

Advantages

Gerald


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## 105542 (Jul 1, 2007)

Should be a triangle wired effect of THREE
1. Wire from car/ battery via a relay to lesuire battery..this is to charge leisure battery. use of relay ....When engine switched off no charge from leisure battery will go back to car battery...
2. then there should be a wire from leisure battery to pms unit and connected to the VAN posistion..
3. The last wire is from the main car battery straight to the pms unit and should be conncected to the CAR position..
Make sure you have the PMS unit earthed properly....should be an earth stud on the unit earth to the van body, there should be an earth at the hook up point to the van body..Also more importantly there should be an earth from the van body to the DC earth connection on the pms unit..

Hope this helps.... :wink:


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