UK Car Repair: water temp gauge ground, water temp gauge, jumper cable

Question
I have a 1965 series IIA land rover. I replaced the water temp gauge and sensor recently and unsuccessfully. I think that because I bought a neg ground gauge and the rover is positive ground is the reason why it won't work. there aren't too many positive ground gauges out there, so I was wondering if there was a work around or maybe a supplier that you can suggest.

Answer
Ordinarily the polarity would not affect the temp gauge. Have you considered converting it to neg earth? It is easy to do.   disconnect the cables from the generator, take a jumper cable from the battery positive and touch it to the field terminal ( the small one-usually yellow and brown) on the generator, it will spark a little, this is normal and it will re-polarise the field coils.