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Big Andy

vdo tacho wiring

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hi dave 

don't know mate ive got the wire harness for the vdo clocks and I think that I have got it right theres a purple wire which is the signal wire and a brown wire which states gauge which I assume that this is for the switch 12v power supply to the clock then theres a red wire which states speedometer 

 

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9 minutes ago, Big Andy said:

hi dave 

don't know mate ive got the wire harness for the vdo clocks and I think that I have got it right theres a purple wire which is the signal wire and a brown wire which states gauge which I assume that this is for the switch 12v power supply to the clock then theres a red wire which states speedometer 

 

That sounds a reasonable assumption, I'd still be popping a meter on their just to make sure nothing weirdos going on! You should see a 12 Volt ignition live signal on the brown wire.

Can you check that the purple links through to the Emerald loom? Presumably the wire tails on the Emerald loom are all lablelled, including one for the tachometer feed?

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Did you have any joy with this? I'm facing a similar issue. VDO rev counter moves slightly but not correctly matching the actual revs.

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No mate I put a resistor in and still doesn't work 

I haven't got a clue what to do next lol

 

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Ok mate, I've not had chance to look into my issue much yet... if I figure it out I will let you know

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Moving slightly but not in proportion to the revs is typically a wrong setting on the tacho, where it's misinterpreting the signal it's getting.

Where they seem to move normally, but at a certain point, after a few thousand rpm or so, suddenly stop reading, then that's often the pull up resistor being required. (Note you can, if unlucky, have a mix of the two, so it misreads, then at a certain point, stops altogether.)

Andy's sounds different, his doesn't seem to be registering anything at all. 

Unfortunately though, he's also using a variety of non standard looms and a less commonly used ecu, on Westfields. They're certainly all good parts individually, but without being there and going through everything with a multimeter, it's hard to know what further to suggest.

Just as a sanity check Andy, do you know if the VDO rev counter has actually been used and working previously?

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Thanks Dave. I have had a few minutes tonight to have a look at this and you were correct it was the settings on the tacho. It appears to be working ok now.

If I can help Andy at all then let me know. I am using an Emerald ECU and VDO guages, with standard westfield main loom and zetec harness. If there is anything you want me to check on my setup give me a shout.

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I had a very quick look at the Emerald software, but not really played with their ecu's for years. 

Is there anything that has to be done on the ecu to enable or configure the tacho drive output? (I couldn't find anything, it was all just shift lights and tell tales).

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7 minutes ago, mattstone79 said:

Thanks Dave. I have had a few minutes tonight to have a look at this and you were correct it was the settings on the tacho. It appears to be working ok now.

If I can help Andy at all then let me know. I am using an Emerald ECU and VDO guages, with standard westfield main loom and zetec harness. If there is anything you want me to check on my setup give me a shout.

Yes you know on the back of the vdo rev counter how's the jumper set 

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I've not changed anything in the ECU software from what Emerald provided me, doesn't mean there isn't anything.

See the picture for my settings

vdo setup.PNG

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7 minutes ago, mattstone79 said:

 

I've not changed anything in the ECU software from what Emerald provided me, doesn't mean there isn't anything.

See the picture for my settings

vdo setup.PNG

Cheers mate all will try that 

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