Ignition switch on older analogue VDO gauge systems

[vas]

are you absolutely sure that while you were tinkering with this fuel gauge, you didn't also move about something else that had foul contact and fixed it without knowing? I mean, if you undo this cable off the fuel gauge, will everything go haywire again?
odd!

re thick cables, trying to sort an issue with my galley fridge power dropping, I went silly with some 10mm2 cables from the breaker around 5m (10m return). Then realised there's no effing way to crimp an normal spade terminal that would fit the fridge danfoss controller!, ended up getting 100mm thinner cables with properly crimped spades and a chock block. Later realised that it's due to tired/wonr breakers so winter project is replacing (most?) these lovely 70s breakers with modern ones. Once I find BLACK breakers at reasonable cost...

V.

 

[BruceK]

are you absolutely sure that while you were tinkering with this fuel gauge, you didn't also move about something else that had foul contact and fixed it without knowing? I mean, if you undo this cable off the fuel gauge, will everything go haywire again?
odd!

re thick cables, trying to sort an issue with my galley fridge power dropping, I went silly with some 10mm2 cables from the breaker around 5m (10m return). Then realised there's no effing way to crimp an normal spade terminal that would fit the fridge danfoss controller!, ended up getting 100mm thinner cables with properly crimped spades and a chock block. Later realised that it's due to tired/wonr breakers so winter project is replacing (most?) these lovely 70s breakers with modern ones. Once I find BLACK breakers at reasonable cost...

V.

Absolutely sure. After testing the ignition switches and swapping them over just to be sure I thought well start unplugging everything one by one until the fault stops. The very first guage was the stbd fuel gauge. I tried it in utter disbelief several times and sure enough the error is repeated. I made some wiring extensions using 1mm2 wire and plugged back in and it's been rock solid for six hour cruising time. As you can see from the diagrams it makes no sense whatsoever.

Interesting comment about the breakers. Yes mine are all old and 20Amp. I have to use inline fuses for my modern electrical equipment

 

[BruceK]

Further reading into VDO (Germany) gauges it would seem there are many vehicle applications where the fuel gauge is associated with a voltage stabiliser. I wonder if that could be the reason behind my issue? I havent seen one but then it may not be in the dash area.

 

[julians]

Further reading into VDO (Germany) gauges it would seem there are many vehicle applications where the fuel gauge is associated with a voltage stabiliser. I wonder if that could be the reason behind my issue? I havent seen one but then it may not be in the dash area.

sounds very much like it could be the case

 

[vas]

I've bought a dozen of dc dc buck converters, using them in various spots throughout the boat

something like that:
4.5-35V 3A LM2596 Spannungs- Voltage Buck Converter 1.23-30V out ESP8266 Arduino | eBay

as I've mentioned in I think another thread, I even use them to stabilise the voltage going to the vdo gauges and through them the senders. That has stabilised my readings no matter I turn on/off dash lights and where the starter batteries stand...

V.

 

[BruceK]

Hot tip! Thanks, just bought a pack of 5 from Amazon