Reserve fuel light wil not work on my early 230 sl

[guyke]

Im building back up my 230 verry early model ,
Im installing the fuel sender .
The fuel Gauge works perfect but the fuel reserve light wil not go on when i simulate an empty tank .
The light itself has been tested and works just fine ,
I have a constant positive feed on the light so thats correct also ,
But there is a strange sort of resistant connected to the gauche .
Could that be damaged
I opened the cluster lightly to see inside without braking the cover .
Can it be removed to test it .
Wat is its function ?
In other forums i read its a bimetal contact that needs to warm up before it triggers the light .
Is this correct ?

[Pawel66]

No, not really. No bimetal there. The resistor is part of gauge for fuel level. Fuel reserve light is a simple circuit where positive is fed to bulb and ground is provided to bulb from fuel sender when float goes down. There is a contact in fuel sender to do this.

The connection goes from fuel sender through tail harness connector and instrument cluster connector.

So either the bulb is burnt, bulb socket not providing contact, there is connection missing on one of these two connectors or contact in fuel sender is not working.

If you say fuel sender works and shows fuel level, I assume ground is provided to the sender.

Become a Full Member here, you will have access to all the required schematics and descriptions. If yoyu are working on a Pagoda, this is a "must be" place and best investment.

[guyke]

Its sad always is asket to get full membership .
I wil stop posting pictures from my restauring proces

[Pawel66]

I have answered your question and added a handful of information.

What else would you like to know? Happy to help.

I would have thought it is perfectly ok to suggest membership. I have not heard about anyone who would regret it. Full membership gives you access to Technical Manual with, actually, just about all there is to know about our cars.

[Benz Dr.]

Early 230SL fuel level senders are different than the tube type senders used on all other 113's. This sender is more like a 190SL or a 220S with an arm with a float on it. The ender has a set of contacts at the fulcrum and this is more likely to be your problem.

Look at the top of your sender inside your trunk. You will need to remove the plastic cover to gain access. There should be 3 wires going to the sender.  Wire for fuel level, ground wire, and wire for reserve light in dash.