Which resistor for Temp gauge sender

Hi all,

Bit of a tricky one that i haven't het found an answer for- hopefully you geniuses can help.

I'm running a 3.9v8 from a disco in my Defender, which has a standard 200tdi temp gauge.

The Temp sender on the V8 isn't compatible with the 200tdi gauge, and it reads off the scale too hot. I understand i need to fit a resistor to the V8 Temp sender to bring it back down so the gauge will be accurate, but does anyone know which type of resistor i need? Can't seem to find a coherent answer so far.

Cheers,
S

1/4 watt will be fine. Use a small ohm rated variable resistor or potentiometer. Get the engine up to operating temp, fit the resistor inline on the connection to your temp sender then adjust the resistor until the gauge reads accurately.

Remove the resistor and read the resistance with a multi-meter. Buy some normal resistors close to the value and fit one inline.

Alternatively, glue the variable resistor so that it cannot adjust and don't bother replacing it. Would probably fair better inside the cab than under the bonnet.

I will be doing this also having just reconnected my "standard" guess the temp original fit land rover gauge, to get back to the OEM look.

If you're not bothered about the OEM look, another approach is to replace the gauge and sender with after market ones which give accurate readings in degrees.

Great, thanks!

:hijacked:

I've been thinking about fitting a led warning light for monitoring the temperature. The gauge is alright, but i want something really obvious for when it's overheating.

I'm thinking something like a thermistor connected to a led.. any thoughts, etc as i'm a proper newb with electronics.

Cheers all- Got a bag of potentiometers from Maplins, I think the one i fitted was 300k ohms. Anyway, ran the engine up to temperature, fitted the potentiometer in the instrument binnacle and adjusted it so the gauge reads in the middle. Glued the potentiometer and checked it. working perfectly.

Thanks for the help everyone!