Just having a cup of coffee and reviewing a few things. In the thread,
https://www.motobrick.com/index.php?topic=6702.0, the Mighty Gryphon mentions "If you want an override switch to turn on the fan when you desire, wire up a SPST switch to Pin E and ground the other side of the switch. When riding, flip the switch and the fan will start. Overtemp light on the dash indicates the override is in use."
Would one access the wire coming out of connection E in the small bottom section of the relay and should this be done in the relay box or can one trace the wire outside of the relay box and tie into it along its path to the water temperature sensor.
I apologize for the multiple questions as my terms may be incorrect and it is likely hard to visualize what I am getting at. I have uploaded eight pictures that go in sequence from the relay box to the wiring coming from the temperature sensor on my 1995 BMW K75 RT. There is text in each pic to provide context and also to ask questions.
Picture 1: Red lines/arrows: “Jumper A2 to 45 will bypass the temp relay and the fan should start. Proves the fan works.” When I tested this the fan ran fine with no unusual squealing noises.
Yellow lines/arrows: “Jumper A3 to ground and the overtemp light should illuminate. Proves the warning light functions.” When I tested this the overltemp light illuminated.
Light green lines/arrows: “Ground pin E will simulate overheating to the temp relay. The fan should start and the overtemp light illuminate. Proves the temperature relay is functional.” Nothing happened when I did this test. Based on the text from the original post this would suggest the relay is not working properly or could it be the temperature sensor?
NOTE: in the top photo in picture 1, the yellow line is off and should be touching pin A3 an the ground pin.
Picture 2:“If you want an override switch to turn on the fan when you desire, wire up a SPST switch to Pin E and ground the other side of the switch. When riding, flip the switch and the fan will start. Overtemp light on the dash indicates the override is in use.”
Connector pin and slot for E indicated by red arrow?
Wire for connector pin and slot E indicated by yellow arrow? Wire appears to be purple and green stripes?
Picture 3“If you want an override switch to turn on the fan when you desire, wire up a SPST switch to Pin E and ground the other side of the switch. When riding, flip the switch and the fan will start.
Overtemp light on the dash indicates the override is in use.”
Picture 4
“If you want an override switch to turn on the fan when you desire, wire up a SPST switch to Pin E and ground the other side of the switch. When riding, flip the switch and the fan will start. “
V/G = Violet (purple)/Green. Is Violet the predominant colour with a smaller strip of green? How do you tell the difference between the two V/G wires coming from the temperature sensor? Note the red box (just outline no fill colour) is the VG wire coming from the temperature sensor and going to the temperature relay in the relay box (see Pic 1)
Picture 5Wire for connector pin and slot E indicated by yellow arrow? Wire appears to be purple and green stripes?
Very little if any slack in the wires to try to tie in here in the relay box.
Picture 6Grounding options for switch wire
Red arrow bolt appears to be a ground for a number of wires. A bit tight here.
Yellow arrows are alternative grounding locations that would require a bolt, nut and lock washer
Picture 7“If you want an override switch to turn on the fan when you desire, wire up a SPST switch to Pin E and ground the other side of the switch. When riding, flip the switch and the fan will start. Overtemp light on the dash indicates the override is in use.”
Can I tap into the wiring that comes from the temperature sensor (yellow arrows)?
There are two wires based on the diagram in Pictures 3 and 4. The V/G wire to tap into should be the one to ground. However, how do you tell the difference between the two V/G wires (See Picture 4) coming off of the temperature sensors as one goes to the temperature relay box and the other to the FI (aka Jettronic control unit?
Picture 8:“If you want an override switch to turn on the fan when you desire, wire up a SPST switch to Pin E and ground the other side of the switch. When riding, flip the switch and the fan will start. Overtemp light on the dash indicates the override is in use.”
The wire from the temperature sensor joins the fuel injector wires in a combined unit (red arrow) that comes along the back end of the air accumulator and then into another wiring loom. There seems to be a wire that comes out of this and appears to go towards the middle of the bike and then into the relay. (yellow arrow) I may have this incorrect.
If correct can I join into the VG wire by opening the sheathing on the wire my finger is touching (yellow arrow)?
Another quick question. If the test of jumping between Pin e doesn't result in the fan coming on, then likely if I wired in a switch as outlined above it would not work, and thus I would need a new relay. However, am i doing the test correctly? See Picture 1 to illustrate how I did the test. Note the gas tank was off and I just had the key turned to on. NOTE: in the top photo in picture 1, the yellow line is off and should be touching pin A3 an the ground pin.