My 425 fan failed!!

[pequeajim]

I noticed yesterday after cutting the grass that the cooling fan on my 425 was not running.

I checked the fuse and it was blown. I replaced it and mowed some more but even though the temp was hot enough, the fan still did not run.

I checked the fuse again and it was ok this time.

I checked the temp sensor contacts and they were closed when the oil is hot and open when it cools off.

I took the fan off to see if anything was not right and it all looks ok. The fan spins freely too!

Any other suggestions?

 

[cqaigy]

you gettting voltage to the fan? or you could check resistance across fan or even run power to it directly to see if it spins.

 

[MossRoad]

I agree. Run power to the fan directly and see if it spins.

 

[stray]

If the motor is bad it couldn't be much different from the set up used on radiators of automobiles. Might be one could match one from a junk yard? Motor, fan, guard and all.

 

[pequeajim]

</font><font color="blue" class="small">( I agree. Run power to the fan directly and see if it spins. )</font>

Moss: I think I read that you have done this with some wire and allegator clips in the past. Where did you connect them?

Battery positive to ?

Negative to chassis?

 

[tracdoc]

Pequeajim,

Maybe take a look at this thread {HERE} from few months ago. Also, FOURTEEN has recommended a number of times jumping the fan circuit such that the oil cooling fan remains ON all the time.

Let us know what you find.

 

[MossRoad]

Not me. Mine's always worked. /forums/images/graemlins/crazy.gif

I'm guessing just take a couple of wire leads and clip them from the battery directly to the fan leads just to see if it spins. If it does, look for the problem elsewhere. If not, the fan motor is probably bad.

 

[pequeajim]

I was looking for the fan leads (bare point of contact), last night. I even took the fan off but the leads on the fan side are sealed, (understandably). I can see the one lead coming off of the temp. switch which I am assuming is the hot wire?

I suppose that I could read voltage by touching the hot side of the switch and chassis.

It was getting dark and I could not see where the other one ended up. I will look again tonight.

 

[bubenberg]

Don't feel like the lone ranger, i am on my third one and a second thermostate including one melted battery top.

I will let you know where i found a less expensive fan, which lasted at least one year. The pt fan did not make it a whole season! Around 650 hours.

 

[J_J]

Automobile radiator fans work good for my 1445. They come in all sizes and around $10 to $20 bucks.

 

[pequeajim]

I checked out the fan today and it must be toast. What did you do, make a custom fan attachment for your tractor? I will have to take a trip to pep boys or something to see what I can find.

I wonder how much I can run this thing without the fan running?

I know there is a discussion going on about oil temperature. I think if it is over 200, I'm probably risking it?

 

[J_J]

Call Terry and get a price first. They might sell only the motor.

Those fans are expensive if you buy new. I would go to a junk yard and pull the size fan you desire.

You might only have to switch the motors. Check it out before you leave the junk yard.

 

[Clarke]

Isn't your tractor still under warranty

sg

 

[pequeajim]

Yes, it is so I can get a replacement from Terry. I was just wondering what I can do right away.

I'll call him.

Jim!

 

[tracdoc]

Is there some intrinsic fault with the fan set-up in these PT's?

Seems like we've heard of a number of failures. It may be that the fan was the primary problem in Pequeajim's unit, and that caused the fuse to blow. The new fuse just sat there unaffected since the motor was now toast.

Getting a replacement fan under warranty is small consolation if these fans are inherently flawed. Do we need to upgrade to beefier fan motors, or is there some flaw with the current circuitry?

 

[pequeajim]

</font><font color="blue" class="small">( Do we need to upgrade to beefier fan motors, or is there some flaw with the current circuitry? )</font>

I will call Terry and tell him about it. After all, our feedback is important for them to make the product better, however, I have read some posts about some fan problems and will investigate putting a stronger fan on the tractor. I am also thinking about putting a better cage over the fan as well as the plastic one that comes with the fan is IMHO not quite as strong as I would like it to be. I can see a big branch going through that into my cooling radiator!

So, I will be hitting the junkyard tomorrow to see what I can pilfer from a wreck or two.

/forums/images/graemlins/grin.gif

 

[pequeajim]

I went out an cut some grass today without the fan running. I don't know if you guys have used a 425 without it running, especially when cutting grass? I happen to have an IR temp gun and checked it every 5 minutes at the side of the tank and the PTO pump (I assume that is the PTO over my right foot?).

I let the temp get to 160 degrees and I stopped. I will let it cool down again and then finish the little bit I have left.

What temp is dangerous? /forums/images/graemlins/confused.gif

 

[Gravy]

I'd guess you might do better to check the temp at the temp switch by the cooler.

Since it's engine oil, I wouldn't worry at all unless the temp went over 230F. Engine oil needs to go over 212F just to boil off the water. That's why short trips are hard on your car engine.

If you get a different fan motor, be sure the amperage draw isn't much more than the original, or add an isolation relay. You don't want to fry your wiring, switches, fusebox, etc... /forums/images/graemlins/shocked.gif

Gravy

 

[tracdoc]

</font><font color="blue" class="small">( What temp is dangerous? )</font>

I would agree w/ Gravy on the temp +/-. Conventional motor oil, like we are running in our hydraulics, is not significantly adversely affected at temps up to 275 F. Much over 300 F these oils begin to show evidence of breakdown. I recall FOURTEEN reporting that he used his wife's candy thermometer to check the oil temp on his, and it was running 180-190 depending on ambient temp {HERE}

The PT-180 does not have an oil cooler, and I would think it does a proportionate workload for its size. I wonder what temps its hydraulic oil reaches...

 

[pequeajim]

Which way does the 425 fan blow the air? Is it out from the engine, or in on the engine?