Overheat light on, fan not starting

[Laitch]

I am not the biggest brick fan fan.

Eat more chocolate, bananas, pizza, and sausage; drink more beer and exercise less. Keep at it and you'll get there eventually—maybe the biggest fan fan ever!    You'll need to upgrade to stronger suspension springs front and rear.

[Mavebrick]

Thank you folks. Will keep y’all posted on my progress (or lack of) periodically.

[Kaos]

Eat more chocolate, bananas, pizza, and sausage; drink more beer and exercise less. Keep at it and you'll get there eventually—maybe the biggest fan fan ever!    You'll need to upgrade to stronger suspension springs front and rear.

 

[Mavebrick]

I bought an aftermarket 12V, 80 watt fan. Seems like it pulls 6ish amps. Is that going to be a problem connected to the line the factory fan was on or is it better suited for a separate
Line connected to the battery directly with a switch and fuse?

[Laitch]

Hopefully your choice of fan doesn't consume excessive current to start up. The problem could more likely be with the rate of air per minute moved by the fan. The output of the Spal 6.5" puller replacement fan is 350 cubic feet per minute. It seems to be a successful replacement. I haven't found the cfm rate of the original equipment fan. Which fan did you buy; can you post a photo of it?

The fan needs to be wired into the temperature sensing switch circuit to run the engine optimally. A battery switch option can lead to overheating from not operating the fan enough, to poor engine performance from operating the fan too much. The engine can be forgiving of inept operation but not indefinitely tolerant. 

[Mavebrick]

Hi Laitch i got a generic radiator fan that fits. Being in Hellton i mean Houston texas i was leaning towards the overkill fan option to keep things cool in summer which is 8months a year. Might have overdone it? Seems like this fan does 1000cfm with 6.67amp draw. I got no clue about the startup draw.

[frankenduck]

If you're worried about putting too much current through the thermo relay then you could power your uber fan with a relay triggered by the VIO/YEL wire that usually powers the fan.

Relay wiring:

85 - Ground
86 - VIO/YEL wire to original fan
30 - In-line fuse to battery
87 - Power out to new fan

[Laitch]

As I indicated, your choice of fan is likely to be ok; don't sweat it— — but frankenduck often has valid workarounds that can help calm the waters concerning outcomes.

The fan will start and stop as necessary—no problem. Don't let that bother you either, that usually means the system is either working appropriately, or there's isn't enough coolant in the system. The main thing is to have clean radiator fins with relatively fresh coolant in the radiator and expansion tank, and refill the system according to BMW's instructions. I change coolant every couple of years but long life coolant is promoted to last around five years.

The fuel tank can get hot to the touch. You can always add a fuel cooler that could decrease the fuel temperature a little. There are a few threads here concerning that. Verify you have insulation under the floor of the tank—stuff like Reflectix that can be purchased at Home Depot. There is a document concerning heat management on the site and even more threads concerning insulation to mitigate temperature swings. MartinW, a member here that lives in a paradisical hell below the equator—has taken several successful steps to cool things down.

[Kaos]

I bought an aftermarket 12V, 80 watt fan. Seems like it pulls 6ish amps. Is that going to be a problem connected to the line the factory fan was on or is it better suited for a separate
Line connected to the battery directly with a switch and fuse?

That should be the same as THE OEM fan, and about 6.6amps. With a 7.5 amp fuse in place you should be solid if it doesnt abnormally drain when starting up.
Looks like a solid replacement. You could directly connect it to the OEM connector with these specs without having the joy of messing with the relay.

If you havent filled up the coolant yet you could still test it with the sensor in hot water and see if it starts and when it starts, it doesnt pop your fuse.
if i remember correctly it should be starting up at 90 celcius (194F )

I do strongly recommend testing it.

[Mavebrick]

Okay just opened my eyes more and looked and am discovering more potential gremlins. What are these disconnected electrical connectors? I have no idea what they do and why there were disconnected by one of the many previous owners. Please advise, thank you. Mainly am thinking it is going to affect the fan functionality via temperature sensor.

[frankenduck]

The second one looks like the hazard switch connector. Non-issue.

If you identify the wire colors to each connector it makes it much easier for us to help you.

[Mavebrick]

Apologize for the poor lighting. First picture is brown and green wire. Second picture is blue/white, yellow/purple and brown wires.

[Laitch]

[Mavebrick]

Thanks Laitch that helps a lot. Looks like i can wire the fan with a switch to the heated grip connector for a manual switch. Will that work? Put the positive of the fan to the green/black with a switch in between and the negative of fan to the brown wire which I am assuming is ground? Seems like fuse 1 is 7.5amp so it could work? I don’t see a specific heated handlebar switch in instrument cluster. Am i missing something?

[Laitch]

The method depicted in this post and the ones after it seems to be the most accepted way to wire up a fan switch. If I wanted a switch, I'd follow a successful method rather than sweat it.

[Laitch]

I don’t see a specific heated handlebar switch in instrument cluster. Am i missing something?

You're missing heated handlebar grips; they're an option at extra cost. No switch is supplied because your Brick apparently didn't have heated grips at original purchase.

[Mavebrick]

Thank you for the link Laitch. I think I am going to wire the manual switch and fan directly to the battery with an inline fuse. Seems like the easiest thing for me to do.

[sooprvylyn]

You don't really need to worry about overheating in texas, as long as your system is working properly. I live in austin and my fan doesn't usually even come on til it's pretty dang hot.  Your bigger issue w the heat is that k bikes are just hot bikes to ride. The tank itself can be a big source of heat. 2 things to help mitigate that are

1. Put a reflective thermal tank blanket under the tank

2. As mentioned above, install a fuel cooler.

I've been looking into a cooler myself for next summer. I'll let you know if I find a good option. The 8" dual pass finned ones that seem to be good fit seem to be missing from the market these days.

In any case, you'll be good w the heat thing til at least April or May now anyway.

[Mavebrick]

Finally managed to get it started again. It was a bad battery. I have insulated the fuel return line and added johnny blanket but work is still in progress. Going to have to take a test ride to make sure everything is good now. The manual fan switch and fan seems to be working but it is very unelegantly attached to the frame with zip ties and the radiator outer metal with zip ties cos fitting it was a massive pain as it was larger diameter than the stock one. Have to take a longer ride to know if the overheating issue is resolved.

[Mavebrick]

I have buttoned it up. Johnny blanket is sitting purely under the weight of the tank and seat and aside from a few trimmings and electrical tape its not really being held on by anything else. I also used insulation foam tape on the fuel return and fuel outlet and a bit of the rail as well. I also connected the rear most stub on the bottom right side of the tank to the hose ending at right footpeg but left the other stub unconnected to anything sitting on the johnny blanket. I just realized i might have just connected the hose for the water and left the vapor vent stub connected to nothing. Is this a problem? I am really looking forward to NOT removing the tank again for a very long time hopefully 😂

[Past-my-Prime]

On my bike they both drain into a little cup that then flows down behind the foot peg on the right. If I’m remembering correctly. I can’t imagine that either drains very much actual liquid — how much rain can collect under the fuel cap, and how much evaporated fuel can condense in that tube?

[Laitch]

I just realized i might have just connected the hose for the water and left the vapor vent stub connected to nothing. Is this a problem?

One problem could possibly be your developing the habit of considering that the engineering elements of your motorcycle are unimportant if providing for their function is inconvenient for you. Another problem could be fuel vapor expansion issues, such as fire hazard caused by fuel dripping from the fuel tank drain stub onto the johnny blanket then off the blanket onto a hot engine.

If there are any adverse effects this negligence, they will likely be revealed in the fullness of time—as usual—so you're good to go. 

[Kaos]

I dont know if i am amazed or somewhat appaled. You do know there is this stuff called firewall/shield for cars and gastanks shielding equipment from heat that have this purpose.
That stuff sticks so damn well and reduces potential heat reaching the gastank.
Now for K-bikes there's a whole lot inbetween the engine and the gastank that makes you not having to worry from the actual engine heat. But maybe the fact that you have a Black gastank in the sun..

[Mavebrick]

Thank you for the advise. To err on the side of caution i will reconnect the hose to the stub closer to the front of the bike instead of the rearmost stub. The water outlet right rearmost stub i imagine is okay to leave open and unconnected?

[Mavebrick]

I have no circlips on my two little rear metal nubs on the tank that goes into frame round holes. Can a cotter pin be used instead or its fine to leave it without? I noticed that other videos mentioned having to remove circlips but mine i guess have been removed in the past by a previous owner.