Mk2.5 1.8 temperature gauge

Technical Area Electrics & ICE
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  1. My model of MX-5 is: __2003
  2. I’m based near: __holywell
  3. I’m looking for technical help or recommendations on: __hi everyone. Im having a issue with my temperature gauge. When the car is warm my temperature gauge sits at the C on the gauge. My heaters are blowing hot air and iv put a new temp sensor in. Iv had my scanner on it and it stays around 90c. Tia
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You’re going to have to chase the wiring back to the instrument cluster, check that and find out if it’s a wiring problem, gauge problem of instrument cluster problem. 1 of the 3 wires from the temperature sensor should be Violet/White, this is the wire that goes back to the instrument cluster. It arrives at the back of the instrument cluster at the end of one of the 2 plugs that are plugged into the back of it. My first check would be to check continuity of that wire.

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Ok thanks mate. I will check the wires tomorrow. Its been working fine. Then all of a sudden it stopped working

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Are your from the Holywell near St Ives, Cambs?

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No mate. Holywell North Wales

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OK. it was just the Holywell I was thinking about is near me and I have a spare instrument cluster should you have wanted to swap the gauge to test it.

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My mistake. Thanks for the offer though bud

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Update. Tried a new cluster and still no change. I have continuity it the wire that goes from the sensor to the gauge. Im a bit stumped what to try next

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Does everything else on the cluster work? With the ignition on, does the gauge move if you ground the wire that goes to the gauge?

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Everything else works. The temperature gauge does move but only just over the cold mark. I haven’t tried earthing it out

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Probably worth checking the resistance of that wire then rather than just continuity.

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I have just earthed the gauge out and it goes straight to hot

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13

Have you checked resistance through the wire?

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No i haven’t mate. Im a bit of a noob with electrics how shall i test it and and what should i be looking for

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The same way that you tested continuity but set your meter to ohms.

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Ok thanks mate. I will have a look tomorrow

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I have resistance in the wire. Not sure what else to try

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Left my car running today. Fan kicked in at 95c then dropped to 85c. I know its only a dummie gauge but its some sort of indicator which is more then i have atm. The temperature gauge goes to the first line but wont go any higher

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There shouldn’t be resistance in the wire. How much resistance is there?

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00.1 as i said im a noob at electrics mate