Help with temperature gauge

[STEVECHIM]

Anybody help me with a temperature gauge problem with my Chim 500?
I had a new gauge sensor fitted to th4e engine (the old one completely failed) but I think it is reading too hot- when the fans cut in (at ?80c), then the temperature gauge reads 100c. Judging by past experience,I think that the fans are cutting in at the correct engine temperature.I think that I need to put a variable resistor in line with the gauge sensor to drop the reading by 20c.

Any advice- roughly how many ohms would reduce temperature by 20c?

Is there an easy way to calibrate the temperature gauge? Is that what I need to do?

Thanks, any advice appreciated

[spend]

If you paid someone to replace it, why dont you ask them if they fitted the correct sensor?

Dave

[mattg7]

I thought I had the same problem with my 400 - reading 110 in traffic and then after moving off not moving very much at all... Try tapping the gauge or driving ove a pot hole - this seemed to cure mine and now reads accurately all time. Fans cut in at the right time and no over heating as yet (touch a large piece of wood!).

[that daddy]

I doubt the fans would come on at 80deg when the thermostat does not open till 82deg,the fans probably cut in around 90deg,well thats what my car indicates,with the old temp tvr sender(but thats irratic)just converted to the rover one with resistor,i done this for my brother about 2 weeks ago and his well happy with the nice consistant readings,rather than the dropping of the temp on a long run where the tvr sender is in the wrong position,he as driving temps of 75to80deg moving and the fans cutting in at 90deg consistantly.

[RumbleBee]

Ive heard about 120 ohms is usually needed when you switch sensors, so get a 200 Ohm potentiometer and youll be able to calibrate it with that. Beware, most PCB grade ones dont quite have a high enough power rating, you will need around 1.2W at 120 ohms (I think - correct me if you know), so a 2W should be fine. Im looking for one myself but the nearest Maplin is miles away.