Wiring the sender direct to the gauge gives bad readings
Obviously the row spec Tdi used the vdo gauges from the then in production td5 so we know the set up works properly
Vdo built the feature into the speedo to correct the gauge reading so rather than start fitting resistors etc I'd find the cause
Try the correct wire size first and then if that doesn't work and you are confident all wires are correctly orientated I'd try and borrow a speedo and or temp sender to try
I mentioned in an earlier thread about damage to the speedo when the wires were being swapped about hmmm I hope not but let's not rule it out
 
Only swapped the sender wire with Earth on the temp gauge so wouldnt have damaged the speedo in any way matey.
Will try a thinner/ normal gauge wire and see if it does anything.
Not a lot left it can be like done most things haha
 
Doubt the gauge of the wire will make any difference. Can you take a resistance reading from the sender body to the battery negative, and then the same from the gauge earth to battery negative?

Maybe the new earth for the sender is not as good as it could be and it is affecting the reading.
 
Holly **** could this finally be over???????
I've know idea what I did but it works!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Got fed up, pushed all connections/plugs into the speedo really hard, checked everything.
Had a cuppa tea and now it fooooking works!!!

 
Edit: Whilst driving it sits about 1/4 or just above, after driving with it sat idling it takes the gauge 10 mins to raise back up to just below centre (normal operating temp)

Is it just my 200tdi being over efficient at cooling now it's cold out do we think?? or still the gauge playing up?
Has got a new ally radiator, viscous fan removed & electic fan in place but not switched on, with a hot climate thermostat fitted, and know all head gasket etc is good so maybe it's just running cool when the rad has air flow?
My old gauge didn't used to do this but is it just because the td5 set up and a new sender with all new direct wiring is more accurate/ responsive?
 
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MaxyMan said:
Edit: Whilst driving it sits about 1/4 or just above, after driving with it sat idling it takes the gauge 10 mins to raise back up to just below centre (normal operating temp)

Is it just my 200tdi being over efficient at cooling now it's cold out do we think?? or still the gauge playing up?
Has got a new ally radiator with a hot climate thermostat fitted, and know all head gasket etc is good so maybe it's just running cool when the rad has air flow?
My old gauge didn't used to do this but is it just because the td5 set up and a new sender with all new direct wiring is more accurate?
Click to expand...
Sounds like it is just running cool which isnt necessarily a bad thing. I'd say that if the temp is varying in the fashion we would expect (hotter in traffic etc) but is just consistently cooler than average id say you were golden!!!
 
Got 1 kicking around somwhere will have to dig it out.
Gun it onto the stat housing?

My stat is 74'C hot climate one as that's what I got as a replacement after mine failed. And what's normal running temp 85-90'C somewhere?
Will see what it's like just after driving when the rad had air flow compared to when it's been sat idling for 10mins with no flow
 
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I can only assume that the modern stepper type? Td5 gauge is more accurate
My old Tdi gauge would be up to temp half way through my 15 min commute where as now it's minutes before arrival with the td5 gauge
Temp sits perfect at just below half and despite driving hard at speed for nearly an hour the gauge remained in this position
Dunno why yours reads low at times but as suggested try a temp test
Can I just say maxyman it's nice having f ing bright easy to see gauges :))) wouldn't u agree
 
Yeh wouldnt mind matey struggling to find mine.
Warms back up to half way when give it some revs for 5mins stationary, soon as start driving it cools right back down again. Should really put a new stat in not a hot climate one as that's prob whats causing this ;)
 
cowasaki said:
I found that on mine too. Just tidied it all up first then connected it up.
Click to expand...


That's what I'm currently in the process of doing, it just trying to match the colours up as someone as changed the top half to all green :S

Am I right in thinking originally (1996 90)

Black - earth
Green - ignition switches live
Purple - permanent live

If so I'm getting somewhere,


Sorry to hijack the thread!
 
TD5dashTDI.jpg
 
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