Radiator fans have stopped coming on. AARRGGHH!

[loader24]

Recently I have noticed that my fans are not coming on when they should. I'm still maintaining 3 bars on the temp indicator, but man is the heat extra intense. I've visually inspected each fuse and none are burned out. So! Where else do I need to check and HOW. I did change the thermostat last year just to let you know that I am capable but none the less still ignorant. Thank you all for your time.

 

[Mellow]

If you're maintaining 3 bars they are either working or the bike is not getting hot enough for the fans to come on... Let it idle in the garage, once it hits 3 bars just wait a bit, if it hits 4 bars they might not be working but they should come on. It's been cooler lately so they probably aren't coming on as much due to the ambient temps but you are also more sensitive as the difference between the bike's normal op temp and the ambient temp is larger.

 

[dduelin]

The fans aren't coming on at all or they are not coming on as often?

As you know the fans normally will only come on when the bike is stopped and idling or moving in slow stop and go traffic. Can you let the bike idle for a while and get the fans to cycle on and off?

 

[Blrfl]

Let it idle for five or ten minutes. If the fans start at all, everything's fine. The ECM makes the decisions about when the fans should run.

If the fans never start, remove and test the fan relay (under the left side cover). If that tests okay, put a test light across the leads that feed the coil, let the bike idle and watch for it to turn when the ECM decides the fan should be on.

--Mark

 

[loader24]

The fans haven't been coming on at all. this last weekend I just took a ride from Savannah to Canton GA, we got caught in a huge traffic jam in Atlanta for about an hour plus, fans never came on the entire time. Which one is the fan relay, I didn't know if it was a fuse or relay or even a separate fuse somewhere else. Your bringing up the ECM scares the out of me, I presume that it also controls the speedometer, because that has intermittently been goofy, like running at 80 then while still at speed dropping to zero then back to 80, it happened on this trip. But the fans haven't been working for a while now, it's just, (I'm sorry to say), I hadn't noticed them not running, you get used to their noise, you know?

 

[Smallville]

So the bike has gone over three bars on the temp gauge?

 

[st1300r]

Fuse letter depends on abs or non abs I think.
It's a 30amp fuse. forward fuse box left hand side.
Pull it and check with and ohm meter or replace it with a new one. It may only look good.

Make sure the fan relay is seated or
pull it and test.
Pull 12v and ground across 85 and 86 on the relay.
Doesn't matter which way, your should hear a click.
Ohmeter across blades number 30 and 87. You should get open with no voltage. And low ohms like less than 1 ohm when 12 volts is across 85 and 86 described above.

The ECM grounds the relay coil when it desides fans are needed based on the signal it gets from the ect engine coolant temperature sensor.

Don't know but there's probably a diagnositc for the ect in the service manual with the bike cold and at operating temp.

BTW is the coolant level full in the radiator?

 

[loader24]

Smallville; Oddly enough I have not had more than 3 bars.

st1300r; I did check a 30amp fuse and it did seem good, none of my fuses are listed with what they go to, in other words there are two fuse boxes and all the owner's manual identifies them with is spares and actives but again I have no clue as what goes with what, as far as relays? Again, same thing, I think I recall seeing what looked like relays to the right of rearward fuse box, other than that couldn't say what goes with what. Also sorry to say I have no idea how to test a relay. I know my ignorance is appalling.

 

[Smallville]

Go through the steps in post 2 before we get too deep. Let it idle and watch the temp gauge. Perhaps they are coming on and you just not hearing them. I have a feeling that if you are not getting 4 bars then they are working. Also make sure your coolant is full as someone suggested.

 

[Blrfl]

(Oops... Smallville kinda beat me to it.)

Before you start tearing up the electricals, start the bike and let it idle for 10-15 minutes. If the fans aren't cycling, the temperature gauge will eventually reach four bars. I've done this test myself by disconnecting the fan motors from the wiring harness. If the bike doesn't do that, you may have a thermostat which has stuck open and the engine is never getting hot enough to need the fans. This is a pretty common thing on this bike, and you'll start to notice that it doesn't hold three bars when the ambinet temperatures drop into the 50s.

Here's a list of which fuses do what: CLICKY and more more than you ever wanted to know about relays: CLICKY.

To identify the fan relay, look at the cluster of them surrounding the fuse blocks. The one you're looking for is in the group closest to the rear of the bike, and it sticks up higher than all of the others.

--Mark

 

[st1300r]

relays