Just finished changing engine on my K1100 RS. I ended up with a LT engine. This engine has a wire and connection from the engine for temp gage.

Being ignorant I thought this connection just should be connected to a temp gage, but I’ve been advised that the connection from the engine and the connection from the gage, has to be connected elsewhere (guessing connections under the tank).

Does my RS wiring have these connections?

That black wire goes direct to the temperature gauge, via a small sub-loom. The other three wires you need (brown, green/black and slate/blue along with a yellow wire for a fuel gauge) should be under the tank in a single flat four-way block. If you look at a wiring diagram it's marked as 'connector for additional instruments'.

New:-

https://www.motorworks.co.uk/vlive/Shop/Parts.php?f=b&T=6&Q=61121459488&q=61121459488&NUFilter=15&Filter=submit

At that price I'd do what I've always done - cut the OEM plug off and make my own sub-loom for less than £10 using Molex connectors or similar. Of course, that does mean changing the connector on the temp/fuel gauges too, but it's still cheaper than the OEM part!

Secondhand:-

https://www.motorworks.co.uk/vlive/Shop/Parts.php?f=b&T=6&Q=61121459488&q=61121459488&NUFilter=10&Filter=submit

Half the price of the new item but still ridiculously expensive for what it is.

Yo brother thanks but WAY to complicated for me with my lack of knowledge.

There are two connections. One coming from the engine and one coming from the temp gage.

All I need to know is:

Does my RS wiring have the two connections the engine wire connection and the temp gage connection had to go in to????

Yes. It's standard on every K but you will need that small sub loom. The gauge needs four wires:-

Brown - earth
Green/black - power
Slate/blue - light
Black - sensor

If the gauge doesn't have those four wires and/or they are not terminated in a flat, four-way green plug then there's no way to get the temp gauge working short of rewiring it yourself.

Anybody got a picture of the connector in the main loom? Both of mine are modded with click'n'lock connectors, so no use to show Danish Biker.

I bought one of those sub looms from Motorworks to sort out the gauge on my 83 K100RS, less than £10.

Dai wrote:If the gauge doesn't have those four wires and/or they are not terminated in a flat, four-way green plug then there's no way to get the temp gauge working short of rewiring it yourself.

The gage I’m buying is with a green connection ready to plug in, the wire from the engine is also in a “ready to plug in” connection. I just don’t know where they go?

92KK 84WW Olaf wrote:I bought one of those sub looms from Motorworks to sort out the gauge on my 83 K100RS, less than £10.

 But since the gage I’ll be getting already is in a green connection would I still need a sub loom? And if yes to you have a link/picture so I can see what a sub loom actually is.

I have 3 gages on hand. All wit the green connection and the “mount-plate” that goes into the engine, but I would bother buy one, if I can’t install it myself.

Find the plug under the tank (on the left hand side, if like a k100) the wire colours will verify you have the right plug.

You need the sub loom, end of story. The black wire from the temperature sensor is a flying lead into the sub loom; it doesn't go anywhere near the main loom. If you don't have the sub loom then you won't get the correct earth, power and light connections. If you plug the temperature gauge straight into the plug on the main loom you will connect yellow to black and it will attempt to read fuel level.

The first link I posted has a good picture. Click on it to enlarge; you'll see the black flying lead. The white plug matches up with a white socket in the main loom. As Daveyson says, it's usually on the left side about halfway between the relay box and the headstock. Don't expect to see it straight away; it's a good bet that it's buried underneath the loom.

The orange plug is for a fuel level gauge.

N

Dai wrote:You need the sub loom, end of story. The black wire from the temperature sensor is a flying lead into the sub loom; it doesn't go anywhere near the main loom. If you don't have the sub loom then you won't get the correct earth, power and light connections. If you plug the temperature gauge straight into the plug on the main loom you will connect yellow to black and it will attempt to read fuel level.

The first link I posted has a good picture. Click on it to enlarge; you'll see the black flying lead. The white plug matches up with a white socket in the main loom. As Daveyson says, it's usually on the left side about halfway between the relay box and the headstock. Don't expect to see it straight away; it's a good bet that it's buried underneath the loom.

The orange plug is for a fuel level gauge.

Sorry I totally missed your links (actually the whole post). Ok I now know what it is, and the price is crazy 

I’m assuming this sub loom is a part of the LT wiring but not the RS. Think I finally understand.

You've got it Two things though:

1. The second link is to a secondhand sub loom taken from a stripped bike
2. Olaf says Motorworks sent him one for £10 (€14?). In my experience the price you see on Motorworks website for secondhand parts is usually the highest you'll pay. It's worth phoning them.

The sub loom is standard on the LT but is an option for all other bikes in the range. BMW used one main wiring harness for every K100 (and K75 as well - I think) and they all have the white socket on them. The fuel injection looms are different though.

Dai wrote:You've got it Two things though:

1. The second link is to a secondhand sub loom taken from a stripped bike
2. Olaf says Motorworks sent him one for £5. In my experience the price you see on Motorworks website for secondhand parts is usually the highest you'll pay. It's worth phoning them.

Mine was new and I recall under £10 so I took it. My gauge hadn't been reading correctly and I hadn't had time to check the cause but the wiring was top of my list. !! PO had bought the gauge and sensor new. 

I've just snagged this lot off ebay UK:

https://www.ebay.co.uk/itm/BMW-K75-k100-k1100-temp-and-fuel-gauge/124267036010?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

I don't really need the sub loom because my bikes are non-standard anyway. I only bought it to have the gauges and sensor as spares. If you're interested, you can have the sub loom for £15 and if you need them, the mounting panels for £2.50p each, plus shipping. PM me if you're interested.