Gauge/dash mystery

So i appear to be having a bit of a mystery, i'm hoping somebody here will be able to help me out.
I have a '86 110 2.5L TD CSW.
So driving around, I was getting high temps on the gauge. So naturally I test/ change the Stat, no cigar. So i run it without a stat, and it gets just onto the dial... until i switch my lights on and the battery indicator gauge goes below red, almost as if off and the temp gauge runs above the half way point (with the stat out, which seems nuts in itself) until i turn lights off and it returns to normal within a matter of about 10 seconds.
It appears to be the case with any higher electrical load.

Thanks for your time, and i hope you can help.

Hello

Shimsteriom said:

Hello

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Hi

Sounds like a voltage regulator problem. The bit on the back of the alternator. Test with multi meter, should be about 12v at batt engine not running and about 14v running.

tottot said:

Sounds like a voltage regulator problem. The bit on the back of the alternator. Test with multi meter, should be about 12v at batt engine not running and about 14v running.

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Or the standard land rover answer to any electrical problem of check all the earths.

Hey all, thanks for the replies, I appear to have fixed the issue. It was one of the following, but i don't know which actually did the trick:
I changed the LED indicator bulb to an incandescent one in the no charge warn.
The Temp gauge -> Temp sensor may have been rubbing on the clamp, and therefore earthing.
I cleaned all the earths for the clocks.
Thanks for your time, you're a couple of stars for trying

Sal