Club 80-90 Forums

Untitled by gary shrigley, on Flickr

I am trying to get the 12v connection to my fridge working.
Should I be looking to run another wire from the vacant spade connector on the relay (see photo above)? If so, where to?
The other 3 connections seem to be correct, but I have no voltage reading at the DIN connection in the cupboard next to the fridge.

James has wiring diagrams including fridge which can be used to review your wiring

https://vwt25.blog/2016/05/13/zig-mc-2000-wiring/

Essentially, the relay is switched when it sees 12v from the running engine, that pulls in the high current circuit to cool the dridge

Thanks for the link. Had a read through and the wiring is much more complicated than my set up as I have no zig panel or leisure battery to worry about. But if I have interpreted some of it correctly it seems I need a link from the vacant spade connection to the main battery positive. Would this work the relay correctly?

Just focus on the relay and the terminal numbers, here's another link

https://www.12voltplanet.co.uk/relay-guide.html

Look at the make & break relay section in particular

terminal 85 & 86 are the switching side, terminal 30 is the high power supply to the relay and 87 the high power supply to the device, in you case the fridge.

I can't see anything relevant in your pic, match up what you have against the wiring diagrams

Thank you again for another very helpful link.
I think I remember my relay numbers as 1,2,3 + 5 which make it a “micro relay”. I also seem to remember that terminal 5 was spare but will check again tomorrow in greater detail.

I don;t think it is a micro relay (too big), but having zoomed in on your picture in Flickr I can see the relay is manufactured by Zig......... shame they don't use the DIN terminal numbers. (too much time around German cars for me) However the diagram on the side is pretty clear 1+2 are the low current coil contacts, 3 and 5 are the high current contacts

So long as you do not mix up the low / high current contacts it'll work if not broken

Sorry about the guess work here but to avoid waiting until tomorrow to get the answer.
1+2 are the red/black connections back to the din.
3 is a green wire coming from my main fuse box which is 12v live
Which would leave 5. Is this the terminal that goes to my positive post on my battery via an in-line fuse?

Guess work on electrics isn't a good idea. There's a surprising amount of energy in a car battery

You can't tell too much from wire colours on a vehicle, except that brown is normally an earth.

I would have expected a fused 12v feed to go to say terminal 3, more likely from the battery rather than the fusebox though. What is the fuse rating for that feed? Possible it could be a switched 12V which only becomes live when the ignition is on / engine running. Do you have a multimeter to check, or can you rig up a 12v test bulb arrangement ?

You really need to trace back each connection

What conversion is this, or is it a home build ?

It is an autohomes conversion.
Ok, I will investigate more tomorrow and come back to you with some acccurate information regarding what terminates on what numbers. Hopefully then you can give me some more pointers.
Thanks again

Some bedtime reading for you:

Really useful site http://www.autohomes.vwt25camper.info/h ... ownlo.html

and pdf with wiring diagram http://www.autohomes.vwt25camper.info/A ... nualWM.pdf

Page 9a has the wiring info for the fridge. I know this is for the earlier air cooled model, but it is more legible than the later manuals also on the site

That looks exactly the same layout as mine on page 9.
I will use that tomorrow to confirm.
Your time and help in solving this problem is most appreciated.

I'll second what 937carrera says.
and just add my 2p worth-
It sounds like the wiring to the relay has been swapped around.
Pin 1 should go to either a switched 12v point on the fuse box that is switched out when the starter motor is turning or to make it easier you can use Terminal G4 on the fuse box which goes "live" when the alternator is running. (green?)
Pin 2 should go to ground. (black?)
Pin 3 should go to battery +ve via a fuse.
pin 5 should go to the fridge +ve. (red?)

[img]https://farm1.staticflickr.com/806/39980410265_63fb7356bd.jpg[/img]Untitled by gary shrigley, on Flickr

Hopefully a little clearer to see. So going on both of your previous advice if I switch the the red fridge connection from 3 to 5 and add a 15 amp fused leg from 3 to battery positive I should be getting a 12 volt reading at the DIN connection below ( with engine running)
[img]https://farm1.staticflickr.com/796/27003960678_dc1b541386_n.jpg[/img]Untitled by gary shrigley, on Flickr

I will look to order one and update you if and when it works.
Thanks again for both of your very informative replies.

[quote="shrig1969"]Sorry about the guess work here but to avoid waiting until tomorrow to get the answer.
1+2 are the red/black connections back to the din.
3 is a green wire coming from my main fuse box which is 12v live
Which would leave 5. Is this the terminal that goes to my positive post on my battery via an in-line fuse?[/quote]

Ah.... so the guess work was a bit off.
If red to fridge is on pin 3 it can stay there and you can connect the battery-fuse-pin 5.
pins 3 and 5 are interchangable.

I can't access the links etc at the moment so not much help on the updates above, but another bit of advice.

You should have two thin wires for the relay coils, feed from fuse 12 and an earth to chassis.

Then there should be a fused 12v feed from the battery to terminal 3 and the connection to the +ve side of the fridge from terminal 5. These will all need to be thick wires. (3 & 5 are interchangeable as suggested above, my logic just makes me think that way)