Yes i tried that - had same outcome: warning after 10 seconds of engine running.

I used a multimeter on the sensor today and have consistently been showing between 5 and 7 volts.

Problem is:

a) I have no idea whether I'm using the multimeter correctly
b) I have no idea whether this current is what it should be on the circuit

So basically I have data and no clue what it means :ROFL:

Any help greatly appreciated

To me, and from MJ stated, that would imply an issue with the wiring.

In terms of the wiring, going by the following PDF from the D2 Tech Dump post, page 8 shows the 'coolant level switch' (F66). It has two wires, a brown one which goes to Earth, and a green with yellow stripe wire going to the instrument panel. It is T32b, the grey block connector, and it's pin 18.

To test continuity, switch your multimeter to 20k Ohms (around the 8:00 position). The display should read 1. Touching both probes together should give you 0. Testing the brown wire should just be a case of putting one probe on that wire, and the other probe to a good earth connection. If the wire is fine, it should read 0. Testing the green/yellow wire involves touching both ends of the wire with the probes (and hopefully getting a 0 reading), but will need the use of an additional length of wire. Just make sure the additional length is fine beforehand. Can't think of an easier way with the second wire.

http://forum.a8parts.co.uk/attachmen...1&d=1695918343

Current Flow Basic equipment From model year 2001.pdf

Thanks Steamship - this is really helpful.

Why would I need an extra length of wire for the green/yellow wire test? Sorry - I am an auto electrics noob....

Also - is there a way to check the connection at the pin? could it be that simple?

I'm assuming that connector is behind the instrument binnacle? Could be as simple as a wire come out I suppose?

For a continuity check of the wire, you need to have a probe at either end, as it's measuring the resistance between the probes. One end will be at the coolant tank where the connector is located (your photo posted earlier) and the other end will be at back of the instrument cluster (wires attached to grey block in following image).

http://forum.a8parts.co.uk/attachmen...1&d=1695987831

In terms of a wire coming out, I would tend to think it wouldn't happen at the instrument cluster end, but there could be a possibility that the connector at the coolant tank end might be further back in the connector than it should be. i.e. whilst being connected, one of the pins was pushed further back, so not making a connection. However, having said that, it doesn't explain how it happened in the first place.

Thanks for this - all understood. I've checked the wires into the plug and actually put a replacement plug in place, disconnecting both wires to the connector at the sensor end, and reconnecting to the new plug, to ensure no corrosion etc causing an issue. All sitting pretty so I don't think its at that end. Could be a break anywhere along the wire I suppose but would be unusual in a sheathed, protected cable I presume? Process of elimination on my side suggested cluster end. That's kind of how I got there.

Checking the continuity of each wire will tell you if there is a break somewhere on them. I'm not sure of where the cable runs, but if visible, are there any signs of it being eaten, although that seems to affect our German members more.

It's a bit of weird one, considering there is a voltage reading between both contacts at the plug means they are both connected to something so I would be more inclined to think one of them could be shorting to something else rather than break in wire. Could be loose connection, sometimes connected like when you measured but coming loose at times. I guess I would first try to rule out problem in dash by shorting the wires by the dash. I had brake pad warning light coming on my ROP S8, It was a break in cable somewhere but I just connected wires behind dash to get rid of warning.

UPDATE: Removed the instrument binnacle and checked the connectors - all seems fine. Nothing obvious. Put it all back together again and now I have the ABS warning coming up as well as the coolant level!!

Couldn't make it up.....

From the wiring diagram this seems to be on the same connector block - T32/b so I possibly need to look at that again or perhaps it just didn't go back in properly?

The retaining lever should lock the connector into place, so unless a pin has been bent when fitting it (which I suspect would stop it from fitting securely), it's sounding more like physical damage to the wiring. Considering the location of the loom, it's difficult to think how any of it could get damaged, especially with the ABS warning now showing after checking the connector.

Grasping at straws here, but has there ever been any work done in and around that area that you know of? Thinking along the lines of someone putting a screw in the wrong place... straight through the loom.

Not that this helps, but here's one part of the wiring loom for the dash/engine bay, that includes the instrument cluster (43), Coolant level (40) and ABS (34) connectors:

http://forum.a8parts.co.uk/attachmen...1&d=1696237339