Oil temperature sender problems

[sjl1]

Hi

wanted to add oil temperature mod that i had on my old k series car to my new sigma, bought a sump plug with threaded hole doe a temp sender from demon tweeks assuming bog standard sender would work but no joy. Ran wire from sump plug sender to gauge via oil/water switch but nada, water temp works ok but oil shows zero. Earthing gauge to earth has no effect so wondering if these caerbont gauges work differently to old fashioned way?

All advice welcomed thanks

 

 

[Jonathan Kay]

You're trying to use the existing gauge with a switch between senders? 

What's the new sender, how many terminals does it have and can you post the instructions?

If you reverse the connections at the switch between the two senders which one then works?

Jonathan

[sjl1]

Am using this http://www.demon-tweeks.co.uk/motorsport/gauge-sender-units/smiths-oil-water-temperature-sender-for-classic-gauges single connection, no instructions

​yes, using existing gauge with switch, have tested wiring and this is all ok

[Jonathan Kay]

http://www.demon-tweeks.co.uk/motorsport/gauge-sender-units/smiths-oil-water-temperature-sender-for-classic-gauges

I'd measure the resistance of the new sender at 0, 20 and 100 °C (with everything else disconnected).

Jonathan

[sjl1]

The gauge doesnt register when sender lead grounded so I don't think its a resistance issue, open circuit or grounded makes no difference

if i can find the water temp sender i can compare but cant find it?

[Jonathan Kay]

I don't understand why it's working with the old water temperature sender but not with the wiring to the new sender shorted to earth. Are you sure that the earth you are using is good?

What happens with the wire at the old sensor shorted to the same earth? And I'd still try reversing the connections at the new switch.

Have you got a multimeter?

Jonathan

[sjl1]

Fixed it, after checking the caerbont wiring diagram on google i noticed  rather unhelpfully the positive and sender connection markings on the loom plug and the associated wires were reversed, this all works until you try to add switched feeds, another example of poor wiring.

Anyway, leads reversed and it worked perfectly with sensible temps for oil and water, a nice hack

thanks for suggestions