Cooling fan blowing fuses

[The Snowman]

Yep, this is my "do maintenance and fuck everything up" day. Probably not related to my issue, but I changed the coolant on Annalisa's 97 900RR today. What a pain in the ass it is to pull and reroute the drain hose from the reservoir.

After all is said and done, I bled it, as instructed in the service manual, letting it run for a few minutes, then cracking the throttle to allow air to come up. When the bubbling stopped and the coolant level started getting higher in the filler neck, I shut her down and put the radiator cap on.

I wanted to make sure that the system was working properly, so I restarted the bike and let it run to get hot. It started getting close to the upper coolant temp and still no fan. I shut it off and checked the fuse. It was blown.

So, I replaced the (friggin tiny) fuse and started it back up. Still no fan. After a minute or two, I shut it down and checked the fuse again. Once again, it was blown. Since I don't have any more extra fuses (where do you get those tiny fuses?), I had to suspend my troubleshooting there.

What could it possibly be? It worked fine the last time I rode it in hot weather, where it would need to come on, which was probably a year ago.

[Degsy]

Wirelessly posted (BlackBerry8330/4.5.0.77 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/105)

Piece of gravel stuck in fan blade or wiring to fan shorted to radiator body.

[stoinkythepig]

Pretty simple circuit on a older bike so probably chafed wiring. Leave the fuse alone for now, you want a dead circuit for this test. Pull the connector(s) off the fan switch which is probably in the radiator and look for continuity to chassis ground on either of them. Trace the one that connects to ground, it is the problem since neither should ever connect to ground. Bear in mind, one should show open circuit and one should show the resistance of the coil in the motor under normal circumstances.

[The Snowman]

Piece of gravel stuck in fan blade or wiring to fan shorted to radiator body.

Good call on the rock. There was a sizable piece preventing the fan from moving at all.

I can't test it now, since I need to grab some fuses. Can you get the tiny ones at auto parts stores or Wally World? They're about half the size of regular car fuses.

[NobodySpecific]

Does it look like the one on the right? If so, then you should be able to find it (or at least a variety pack that contains one) at any auto parts store near you

[The Snowman]

Does it look like the one on the right? If so, then you should be able to find it (or at least a variety pack that contains one) at any auto parts store near you

Yeah. Mini-blade fuses.

[stoinkythepig]

Good call on the rock. There was a sizable piece preventing the fan from moving at all.

I can't test it now, since I need to grab some fuses. Can you get the tiny ones at auto parts stores or Wally World? They're about half the size of regular car fuses.

That was a good call, wish I'd thought of it. Bet that was it.

[Degsy]

Wirelessly posted (BlackBerry8330/4.5.0.77 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/105)

Good call on the rock. There was a sizable piece preventing the fan from moving at all.

I can't test it now, since I need to grab some fuses. Can you get the tiny ones at auto parts stores or Wally World? They're about half the size of regular car fuses.

That was a good call, wish I'd thought of it. Bet that was it.

I'm Gregory Fucking House.

[The Snowman]

I'm Gregory Fucking House.

Without the cane and ball.

[Degsy]

Wirelessly posted (BlackBerry8330/4.5.0.77 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/105)

Yeah, or the cbr.

[The Snowman]

Yeah, or the cbr.

Then get yourself one, son.

[Degsy]

[The Snowman]

Love how he tucks the cane away somewhere in the subframe.