2004 R1150RT Electrical Schematics (Twin Spark)

[roger 04 rt]

I make frequent use of Doug Raymond's excellent R1150RT_Elec_Diagram (link below). It is much easier to navigate than my Clymer's Manual and clearer than a BMW schematic I've found on the web. However, for those of us who own the 2004 Twin Spark RT, it is missing the connections for the main spark plugs, which led me to purchase the BMW SLP 2.2 Electrical Diagram CD.

 

The differences between Doug's Schematic for the single-spark 1150RT and the twin-spark are:

 

--There is a Fuse 9, 7.5 amps. It connects to the High Beam lamp and indicator, between the Load Relief relay and the High Beam switch.

 

--There are two connections from the Motronic to the connectors on top of the Stick Coils. The left side and right side have separate connections to the Motronic. +12V for the stick coils comes directly from the Key Switch, no fuse.

 

(--Some R1150RT models have a second Load relay (not mine) that connects the main plug stick coils to +12V via a direct connection when the key is on. There is no indication of which VINs have this relay.)

 

--Errata: On page 3 of Doug's schematic there should be a connection from the Load Relief relay to Fuse 7.

 

I've uploaded the links and PDF files that show the wiring in detail for those who need to troubleshoot a problem.

 

1. Doug Raymond's original schematic: R1150RT_Elec_Diagram

 

2. An updated page 3 of Doug's R1150RT_Elec_Diagram: R1150RT_Elec_Diagram Page 3 Updated

 

3. BMW Schematic showing Fuse 9: 2004 R1150RT High Beam Schematic

 

4. Twin Spark Connections: 2004 R1150RT Twin Spark Connections

 

5. Twin Spark Connections with Load Relay (not common): 2004 R1150RT Twin Spark Schematic Load Relay 2

[roger 04 rt]

Those of us who own twin-spark 1150s can thank Doug Raymond again. He has recently posted a twin-spark R1150RT electrical drawing. Neither Clymers nor Haynes ever added twin-spark detail. They also lack the correct fusing for headlights. Doug added the headlight grounding configuration, showing them grouped and grounded by a single wire.

 

Of course the biggest gain on this schematic is the wiring detail for the stick coils.

 

Although these schematics are for the RT models, the detailing of the Motronic inputs/outputs and other sensors related to starting and running are, to the best of my knowledge, the same.

 

RB

 

Link: Doug Raymond Ladder Logic Schematics for R1150RT Dual Spark, R1150RT and R1100RT

[dan cata]

Could we have more pinned topics please?

 

Roger, you are of a real value to this forum!

 

Dan.

[roger 04 rt]

Here is a very interesting problem found on an R1150RT 2004 with the second Power (like Load Relief but not) relay. The detail to find this is only on BMW source documents SLP 2.2 and on the Twin Spark schematic I put together with Doug Raymond. Here Doug Raymond Schematic List.

 

 

 

Well.... the problem came back.... with rough running and surging ...

 

This time, I cleaned the combustion chamber with a can of the Berryman's combustion chamber cleaner that comes with a hose and gets delivered through the vacuum lines. (I assembled a "t" connection and two more vinyl tubes to deliver it to both cylinders at the same time.

 

A lot of carbon came out of the back after the process but the stalling was still there.

 

I found a YouTube video for checking the spark on the Stick coils (of which, one was replaced by the previous owner about two years ago, and the other by me when this problem first started.

 

I discovered that none of them gave sparks, so I left them unplugged and removed one secondary plug at a time; the engine stopped almost right away and would not start with the secondaries unplugged and only the main plugs securely connected.

 

My suspicion then turned to lack of 12V current to the primary plugs and that the bike had been running on secondary plugs this entire time :banghead

 

After finally finding the wiring diagram for the dual spark '04 R1150RT, which is quite difficult to find, I came across the remark that some bikes of this model and year have a Load Relief Relay for the main plugs and the wire is of a different color.

 

Part of the reasoning was that in the bikes without the relay, the same 12V line feeds both sets of plugs, therefore, if that wire had been damaged, I should not have a spark on the secondary plugs either; instead, I have one 12V line to my main plugs and one line to the secondary plugs.

 

Here is the process of elimination that I followed based on the wiring diagram by Dough Raymond available here: R1150RT-2-Plug-Elec-Diagram-V1_1.pdf

 

Unplug the wire connectors to the stick coils and note their colors:

 

Left cylinder.

Brown (ground from the HV coil)

Green with black line (12V)

Black with violet line (Motronic)

 

Right Cylinder.

Brown (ground from the HV coil)

Green with black line (12V)

Black with green line (Motronic)

 

The 12V wire is solid green in bikes without a load relief relay and green with black in those that have it. (Nobody seems to know why only some bikes have this)

 

With the ignition off, I checked conductivity on the green/black wire from one cylinder to the other and ground connectivity from each of the brown wires; all ok

 

With the ignition ON, I looked for 12V at the Green/Black wire and found none. That is why there was no spark on the primary plugs.

 

I opened the fuse box and found a yellow relay in the position 11 (See picture below) that is not present in other dual spark RT's of the same year.

 

The relay was loose... it took some work to hold the relay holder from below to correctly and fully engage the relay but after that I was able to read 12V at the connectors to the coil sticks, the bike runs as it should.

 

I also checked the coil sticks for conductivity and they are true and correct.

 

As the engine speed now climbed at IDLE to almost 1600 rpm, I adjusted it and balanced throttle bodies. It's all good now.

 

I hope this helps someone one day.

 

 

Edited June 19, 2013 by roger 04 rt

[Conestogaman]

Thank you for the info! 7 years later, and you're still helping RT owners!