Triumph Spitfire gauge readings - uddy
Last summer I thought I had a water cooling problem when my temperature gauge would quickly rise to ¾ of full-scale. After all the usual thermostat changes, flushing rads, checking water pump etc, I noticed that when I half filled the petrol tank its reading was full-scale. Ah ha - changed the voltage regulator on the back of the speedo and hey presto, water temp is now between ¼ and ½ of full-scale and petrol gauge is OK.

However ... I now have 2 new problems
1. If I turn on my headlights when driving, the temp gauge rises to ½ full-scale.
2. The speedo back-light comes on OK when the lights are turned on, except when the engine is running, when it then goes off. (Is it a coincidence that the voltage regulator is fixed to the rear of the speedo?)

Any suggestions gratefully received.

Triumph Spitfire gauge readings - Andrew Moorey (Tune-Up)
Check instrument panel earths and engine to chassis earths.

Simplicate and add lightness!
Triumph Spitfire gauge readings - Peter D
This car had a voltage regulator a 3 pin metal can device that fed all the instruments feul temps etc. This was a crued device usin a bimetalic stip and a heater coil. Look in the cct diagram for this device as I think that is your problem . The back light is not related and probably due to vibration and duff bulb. Regards Peter

Value my car