Oil temp gauges

[thrang]

Any one know anything about wiring in an oil temp gauge? The gauge fitted on bimbo2 has four wires, and the sender has only two... Although I'm pretty good with mechanical issues I'm a bit of fuc*wit when it comes to the dark light of electricky.... especially when there is no wiring diagram.

[Justin B.]

I have no idea but suspect that two of the gauge wires are for backlighting?  How is it wired into the other bike?

[thrang]

thats the problem the sender was fitted but not wired in, and there was not a diagram. I can snap a piccy of what I got if it might help?

[Bob_Roller]

I'll go out on a limb here, so anyone correct me if I'm wrong! Your temp sending unit is most likely a thermistor, a temperature sensitive resistor. I think you need a wire from the bikes electrics to supply a 12 volt positive 'switched', only has power when the key is on, to one terminal of the sender, the other terminal would have a wire  that goes  to the indicator, the other wire from the indicator would go to ground, earth, chassis whatever term you use. You need to determine what 2 wires provide power to the internal lighting. I don't think you can harm the indicator, but you may want to run this by someone more experienced than I am. Let me know if this works!

[thrang]

Cheers Rob. I'll have a look and let you know.
Tony

[airhead]

On the back of the gauge, especially if it's a VDO, there will be three spade terminals, +,  -  and S. Fairly self explanatory, but + has 12V from the ignition cicuit, - is to ground (or negative) and S goes to the sender, which is screwed into the sump somewhere (I machined the sump plug to take mine) and relies on ground return so only needs the one wire. The remaining two wires on the back are for the lighting, so you can simply jump one of them down to the negative spade terminal (this presumes it's the later style, and not the older one that has a metal gauge body and self grounds).

Bill...............;-)

[thrang]

On the rear of the gauge there are no terminals just four wires. Black, yellow, blue and red I'm assuming the black is the earth (as I've found a lose black wire earthed to the frame under the tank) and the red is live. I'll take a live feed off the ignition to the red and I'm just working through it using trial and error and sooner or later I hit the right combination.

[airhead]

What make is the gauge? Maybe I can find a bit more about it.

Bill..............;-)

[thrang]

Just says oil temp gauge on it, no other markings or manufacture label.

[airhead]

Oh!!! Or to put it another way..............Yer on yer own!! LOL

Not really, just work logically I suppose, along the lines you talked of before. Do you have the sender? How many connections on it, there only needs to be one and it will be presumably the yellow or blue one, the one left is most likely the gauge illumination.

Bill...................;-)

[Justin B.]

I would also assume that:

-  If the sender has only one wire/terminal then it most likely is a variable resistance that effectively connects between the gauge and ground.

-  If the gauge has two terminals/wires them possibly +12 volts hooks to one of them and the other goes to the gauge.

[Bob_Roller]

Just on an informational note, our bikes use a solid brown wire for grounds, earths. I'm sure there are exceptions, and this is a US model that I have the diagram for and consistency in colored  wires used sometimes doesn't match the wiring diagrams.