Non working Rev and ecometer

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Bonymaenjack
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Post Wed Jul 13, 2016 3:03 pm

I 've had to replace my wiring loom and fuse box due to a fire , everything is now working as it should with the exception of the Rev and ecometer ,these were working before the replacement work was carried out. I've bought two "working" instrument clusters but both have the same issue of a non working rev and ecometer .I wonder if due to the fire this has caused a problem with the ecu , the car now starts and runs .Any advice would be gratefully received .
I replaced the fuse box and associated loom along with the ABS loom but neither ECU's
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Brianmoooore
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Post Thu Jul 14, 2016 10:39 am

Strange. Although the econometer and the rev. counter are part of the same instrument, they are completely separate, and use two completely different signals from the ECU. The rev. counter is driven by the plain black 'engine speed' signal, and the econometer uses the white/black (changing to white/yellow) 'fuel rate' signal, both derived from completely different sections of the ECU.
You haven't used a really early loom, where these signals went via a separate three pin plug, and not through the C101, by any chance?
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Bonymaenjack
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Post Thu Jul 14, 2016 12:23 pm

Brianmoooore wrote:Strange. Although the econometer and the rev. counter are part of the same instrument, they are completely separate, and use two completely different signals from the ECU. The rev. counter is driven by the plain black 'engine speed' signal, and the econometer uses the white/black (changing to white/yellow) 'fuel rate' signal, both derived from completely different sections of the ECU.
You haven't used a really early loom, where these signals went via a separate three pin plug, and not through the C101, by any chance?
Thanks Brian for the reply, the age of the loom is unknown (bought from Fritzs Bits) , the colour codes are virtually the same but I suspect it;s from an earlier year than mine .I've connected each wire individually with solder and I believe that all s correct,I haven't bypassed any of the C connections . Can I assume I can test a signal from the coil (the black wire feeding into the connector into the instrument cluster ) either for continuity and power ?
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Brianmoooore
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Post Thu Jul 14, 2016 3:16 pm

Oops! Posted the answer to this on your fuel gauge thread!