Coolant level sender with flat pins

[FEP]

A retailer who I will not name at the moment, sold me this coolant level sender and persuaded me that the correct one for an M3 has flat connectors and not the round connectors of my old one. He said that a dealer one will also have flat connectors and a round connector part is not the correct length leading to coolant level mis-reads.

He seemed to think that the round connector ones are a different length and used for different (later type?) expansion tanks.

Now I see that according to the ETK, its the same sender for ALL 2.0L+ E30's and of course on the end of my loom lead is a female round connector - albeit broken and in need of replacement.

Is he right or do I just bite the bullet and buy a dealer part?

Anyone know the part number for a new plug?

[clipper]

I have both types in my spares stash so just went to have a look.

They are both identical in length.

[FEP]

I have both types in my spares stash so just went to have a look.

They are both identical in length.

So the only difference is the terminals?

[clipper]

As fas as I can see, yes.

[FEP]

As fas as I can see, yes.

Thanks for checking for me.

[clipper]

The flat pin one has part no 1375715 and real OEM lists that as being up to 9/1986
The round pin is part no 1378320 and real OEM lists that as being from 9/1986

[FEP]

The flat pin one has part no 1375715 and real OEM lists that as being up to 9/1986
The round pin is part no 1378320 and real OEM lists that as being from 9/1986

Thank you my friend - good work!

I prefer the display on BMWfans, but now I discover that Realoem is more thorough with part dates.

So it was C3BMW who misled me, though I've generally found them to be OK. Suspect that they made a genuine mistake over the new Vs late.

Still need part no for the plug.

[Brianmoooore]

There are still two versions of the sender with round pins, and I've been sold the wrong one in the past by another well known retailer.
M20 coolant bottles use a sender that switches the light off when the float is is closest to the terminals end, but radiators that have a built in coolant tank (M40, M42, M50, etc., etc.) have the sender fitted upside down art the bottom, so switch the light off when the float is farthest away from the terminals.
Fit the wrong one, and the light will be on when the tank is full, and off when it's empty.

[FEP]

Thanks Brian. What a minefield!

Still hoping someone knows the p/n for the plug!

[polsta]

interesting

how on earth can i check ?

my coolant lights has never worked, i bought a new sensor from euros , but it was the same, so figured there was a fault in the loom ? but its possible my old sender was knackered, and ive been sold one of the ones you mention that does it the wrong way round ?

i need to get this fixed but know nothing about this sort of thing and how best to go about it

[Brianmoooore]

Sorting the two pins in the connector together with a bit of wire should keep the LED off. If the light still comes on, lift the sensor out of the bottle, with its wire connected.
If the light doesn't come on with the float right at the bottom, then you have the wrong version.
There's a small difference in length between the two versions, IIRC, but nothing you would notice unless you had both types side by side.