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Cooling Fan Melted?

Ruggybuggy

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Has anyone had their cooling fan melt of the motor shaft? I had my engine overheat in stop and go traffic and realized the fan wasn't coming on. When I inspected the fan it had melted of the motor shaft. :confused:
 
Its possible. There was one restrainer that didn't have anything in it. It was only melted on one side of the mounting hole. I would have thought the fuse would have blown before it was able to spin off the shaft.
 
I had the plastic blades melt and fail on an Accord years ago. Also, an A/C clutch melted down on another Honda.

Now as to where the excess heat came from to cause this. Thermostat function and fluid level is the first check.
If these are OK and you see no blade/air flow obstruction the fan motor may have overheated w/an internal issue.
This is not normal and you need to know exactly why this happened. Good luck and keep us posted.
 
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Sorry for the late reply. The melted fan blade was caused by a rubber hose that had found its way out of it retainer and ended up in the blades. The fan motor managed to spin the shaft in the stationary fan and melt the plastic. The fuse should have blown before this happened. I managed to find a used low use fan on ebay for $25. I installed it on Saturday and everything is back to normal.
 
Sorry for the late reply. The melted fan blade was caused by a rubber hose that had found its way out of it retainer and ended up in the blades. The fan motor managed to spin the shaft in the stationary fan and melt the plastic. The fuse should have blown before this happened. I managed to find a used low use fan on ebay for $25. I installed it on Saturday and everything is back to normal.
I noticed my fan wasn't coming on awhile back, same thing happened to me with the hose blocking the fan. I was lucky, I put the hose back out of the way and the fan just came on, but same problem with the fuse not blowing.
 
My feeling is that Honda made a mistake with the fuse size. The fuse should blow before any damage could occur to the fan. I still have the old fan and it still works. I'll experiment with different fuse sizes and see what one will "pop" when I lock the motor's shaft.
 
My feeling is that Honda made a mistake with the fuse size. The fuse should blow before any damage could occur to the fan. I still have the old fan and it still works. I'll experiment with different fuse sizes and see what one will "pop" when I lock the motor's shaft.
That would be great. I did my valves in the beginning of November I think, and I didn't notice my fan was being pinched so it couldn't rotate until April and I ride 4 or 5 times a week year round.
I'm mostly on the freeway and that was the coolest time of the year and I'm not actually sure it was blocked that whole time (don't know how else it could have gotten pinched in there like that though) but who knows how many times my fan tried going on and couldn't move, but kept on trying.
 
Fuses are to protect electrical components, not mechanical ones.

If your wires melted when it did this, it would have been mis-designed.
 
Fuses are to protect electrical components, not mechanical ones.

If your wires melted when it did this, it would have been mis-designed.
Wouldn't the motor being physically stopped cause a electrical surge?
 
Wouldn't the motor being physically stopped cause a electrical surge?

I'm willing to bet that if the fan hadn't slipped the shaft, then the fuse would have blown before the wires melted. As noted, the fuse is sized to protect the electrical components. The mechanical connection between the motor shaft and the fan appears to be the weak point in the whole system (not surprising to me, the plastic fan is probably just pressed on to the shaft).
In this case, the fan separated from the shaft before the motor rotor became blocked, though a blocked rotor would probably blow a fuse due to a current spike. As the purpose of the fuse is to protect the electrical components, and no electrical components were damaged, the fuse cannot be said to have failed/been oversized.
 
Glad you found/fixed the problem.

There are 57 pages of very specific cable/harness routing on the various NC models to avoid interference.
Even the handle bars have punch marks and are clocked at a specific position.
If a tie wrap or hold down comes loose there will be trouble as everything is in close proximity to one another.
 
I haven't had a chance to test a fuse size but will next week. I'll run an amp clamp around the wires when I lock the old motor and see what it will draw then will choose a fuse accordingly. Yes a fuse would protect the wires but a system designed to actually cause damage to the fan if it gets jammed is a poor design. I was luck that it didn't harm my rad. The melted fan had actually leftmarks in the rad.
 
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Well I did the test on a locked motor with different sizes of fuses. I went down to a 5amp and the fuse would not blow. Then I started to actually "think" and realized this wasn't going to work. Electric motors will draw the same current whether it's locked or not. The motor is turn by magnetism and amperage doesn't change because the armature is locked.
 
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Well I did the test on a locked motor with different sizes of fuses. I went down to a 5amp and the fuse would not blow. Then I started to actually "think" and realized this wasn't going to work. Electric motors will draw the same current whether it's locked or not. The motor is turn by magnetism and amperage doesn't change because the armature is locked.

I think the motor current does change based on whether the motor shaft is spinning or not. A stopped motor requires more current to get it running than it does once it's running. Measuring the current flow with an ammeter would be far more accurate than just trying different fuse sizes.

Nonetheless, I think you've demonstrated that using exact fuse sizing to protect against this mechanical failure is rather futile.
 
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Ruggybuggy;190768 Electric motors will draw the same current whether it's locked or not. The motor is turn by magnetism and amperage doesn't change because the armature is locked.[/QUOTE said:
Depends on the type of motor. The only way to verify current draw is with an amp meter.
 
The root cause for the fan failure was caused by (A) by not replacing the hose in the retainer or (B) the retainer failed. If the hose securely clipped back into the retainer after the fault was discovered then was it really the retainer that failed?

A was self inflicted. B could be bad design of the retainer but if that is true and you still trust it after finding the hose loose than go back to A.
 
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