Cooling fan not engaged

Busarider007

Registered
Recently I noticed some coolant leaking and it was coming from the coolant pipe below, the clamp was loose.
Anyway, during stop n go traffic the bike was red lining and the fan not kicking on at the half mark.
It would come on intermittently for a few seconds and shut off.

Today I jumped the fan from the thermoswitch and the fan works great, coolant circulating and temp is normal.

Question is...can the thermoswitch be busted or is it the thermostat or air in the system?
 
I'd bet on air given your post. Burp the cooling system and add the proper coolant to fill the system. Gen I I'm guessing. They have cooling issues , especially in stop and go traffic.

Once you get the cooling system squared away if you continue to have problems you need to make absolutely sure that everything in the system is good. Thermostat, water pump, radiator.

If everything is perfect you can change the cooling fan. Muzzy has an improved flow fan blade, you can add a second fan, you can relocate the the cooling fan switch, you can wire the fan circuit and add a switch allowing you to turn the fan on manually .......
 
I had a cooling problem on my Gen 1 that I have. I put the Muzzy Fan on like dadofthree mentioned and Problem Solved. Better check the other things he mentioned first though.....:goodidea:
 
Fan switch fitted to the LHS of the rad on my Gen 1 failed....bridged the connector with a bit of wire to prove the fan was OK then as part of a coolant change I fitted a new switch.
Air would cause overheating but can't see it affecting the fans like that.
 
burp it for sure as stated. maybe fan switch. when you figure it out consider putting a muzzy blade as stated above and a lower temp fan switch as well as engine ice. I did these changes and i have a 1397 and its cools city at all times never even makes it the half way point
 
I took off the theromswitch and it was covered in crap, cleaned the brass tips clean and threaded back.
However there was no continuity at the connectors, so I'm guessing the switch is dead.
Now the O ring broke and have to get a new switch with O ring:banghead:

Fan's working ok tho when jumped. I think I'll leave the bridge until I get a replacement.
Will consider adding a muzzy blade, too much of stop n go traffic in the city.
 
If the switch was covered in crap you might consider flushing the system and changing the coolant.

You will not have continuity until the switch is heated to it's operating temperature. It closes then completing the circuit and operating the fan.

I didn't check the drawing, so that's all guess work on my part.
 
I have replaced many fan switches for the same problem. 97 Honda accord switch works pretty good. Even comes on at a lower temp. Plug isn't the same though. But with a little ingenuity you can get around that.
 
I took off the theromswitch and it was covered in crap, cleaned the brass tips clean and threaded back.
However there was no continuity at the connectors, so I'm guessing the switch is dead.
Now the O ring broke and have to get a new switch with O ring:banghead:

Fan's working ok tho when jumped. I think I'll leave the bridge until I get a replacement.
Will consider adding a muzzy blade, too much of stop n go traffic in the city.
switch is a temp switch, did you heat it up??
 
the temp sensor is high up on the radiator. since you had a leak the coolant probaly dropped below the sensor that turns the fan on. refill the radiator and check it from there
 
the temp sensor is high up on the radiator. since you had a leak the coolant probaly dropped below the sensor that turns the fan on. refill the radiator and check it from there

I think you nailed it Gixx, each time the level went down from the leak the fun would not kick in. Refilled the rad and it seems to be working fine. I'll monitor for a few days. The bike wasn't heating up today and the fan kicked in at mid-level.
 
I think you nailed it Gixx, each time the level went down from the leak the fun would not kick in. Refilled the rad and it seems to be working fine. I'll monitor for a few days. The bike wasn't heating up today and the fan kicked in at mid-level.

very good
 
I noticed today that the fan kicked in around the half mark, shut down and when the gauge was at the 3/4 mark the fan didn't kick in when bike was stationary.
Is it supposed to run continuous until the temp is lowered? Never really paid attention to the fan workings before.
 
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