Trident fridge not working on 12 volts

[elsid]

The fridge on my 1985 A/S Trident works on mains and gas but not on 12v when on the move. I decided to check the supply to the fridge before ripping it out. I found a relay behind the panel above the sink unit. There are two switches on this panel, one for the water pump and the other goes to the relay. With this switch on and the ignition on the relay activates OK. Terminal 85 on the relay goes to terminal 11 on the Zig unit (CF9) which then goes through the 15 amp fridge fuse to terminal 12 and then, I presume, to the fridge. The problem seems to be lack of volts at terminal 30 on the relay. There are two wires on the car battery, one with a 25 amp fuse which goes to terminal 2 on the Zig unit, and one with a 15 amp fuse which should go to terminal 30 on the relay. I have checked the fuse is OK but the wire at terminal 30 is dead! Does anyone know where the wire from terminal 30 goes and what route it takes? The cable comes through the back of the battery box, where the table is stored and disappears under the carpet. I have checked in the back of the cupboards but can't find out where it goes. I suspect there is a break in this cable, if I can't find it I may have to lay in another cable. Can anyone help.
Sid

[Grun]

Sid,
Just a thought..... what sort of fuseholder have you got at the battery connection to the cable that feeds terminal 30. Just wondered if although the fuse itself is ok it may not be making good contact in the holder.

If you can get at the bare wire at each end of the cable do a continuity check using your multimeter (set on ohms) between the two ends using another bit of wire to extend one of the meter leads. (Or a battery, bulb and a couple of bits of wire).

My Autosleeper has no zig, but a self fitted leisure battery and split charge relay. Everything currently working (Touches wood while typing )

[elsid]

Hi Grun,
I have tried all those options, I was able to get a probe into the fuse holder to check the current was getting through. It lit up a 21 watt bulb OK. All the wiring diagrams I have seen are different from my van but they all show the wire at the battery with a 15 amp fuse going to terminal 30 on the relay. I was thinking there may be a switch somewhere on the line in my van!! I have drawn up a diagram for my van based on all the checks I have done while trying to sort this problem out. I have just got to sort this last wire.
Regards Sid

[Grun]

Sid,

You asked.......

Does anyone know where the wire from terminal 30 goes and what route it takes? The cable comes through the back of the battery box, where the table is stored and disappears under the carpet. I have checked in the back of the cupboards but can't find out where it goes

When I was doing a bit in the area of the cupboards some 8 years ago the domestic electrics were routed as you say up the back of the cupboards and inside the left side of the plastic (fibreglass?) trim surrounding the louvre window above the sink unit. (Mine is an '86 poptop Autosleeper) Cables also were routed up the right hand side. Nothing looked well installed, masking tape was securing some of the cables in position. This was original conversion workmanship, the vehicle was sold to me by the first owner from new, and I still see him from time to time.

I have had a look at the wiring diagram for the zig (CF 8....Probably similar) on the wiki, cannot see what would cause your lack of continuity.

Mike

[elsid]

I have ignored all the diagrams I have seen and started checking through the system from scratch. I don't know what the circuit is like in the CF9 Zig unit so have checked through the external wiring. The relay is activated through the ignition switch and a switch in the panel over the sink unit, this bit works fine. The fridge supply goes in the opposite direction to the other diagrams I have seen!! It starts at terminal 12, on the Zig, going through the Zig unit 15amp fridge fuse to terminal 11. From there it goes to terminal 30 on the relay, through the relay to terminal 87 and then to the selector switch on the front of the fridge. I have checked the circuit from terminal 12 through the various switches and through the 12 volt element, every thing seems OK. The problem is terminal 12 is dead. I am assuming that the wire on the engine battery with the 15 amp fuse should go to terminal 12 to supply the volts!! I have tried all combinations of switches on the Zig unit with and without the engine running to no avail. I tried it with the engine running because on my car the split charge relay only operates when the engine is running and the alternator is producing volts.I am considering running another cable from the battery to terminal 12 to see what happens!!