PT422 Cooling Fan Problem

[BobRip]

Well today I noticed that the green light on my cooling fan monitor did not come on. I check the fan and it was not running. I checked the hydraulic reservoir and it was very hot. Anyway, after several false starts, I traced it down to an insulation piercing connector (I call them devil clips). It was connecting the wiring harness to the power wire for the fan. This is located on the left side of the PT. I took it apart after cutting through two layers of heat shrink. I removed the devil clip and soldered the wire in place.

These devil clips are about the poorest excuse for a connector I have ever encountered. I have had two fuse holders (which use the same insulation piercing technology) fail, plus this recent failure. I should remove them from my trailer, although none have failed yet. I have seem problems on other trailers and vehicles.

Too get to this wiring harness I had to remove a strap that was bolted to the side of the PT. Then I unplugged the connector from the harness to the engine. I have about 700 hours on the PT.

 

[cqaigy2]

Sorry your fan stopped working, but glad your light alarm worked.

I feel fortunate not to have had many problems with the "diablo" clips


Thanks for the pictures and description of your repair.

 

[MossRoad]

My fan stopped working last fall. I did not need it this winter and I haven't mowed the lawn but three times this year. I needed to do some heavy work a few weeks ago and went to track down the fan problem. The fuse was good so I suspected the thermostat. But I found that I was not getting 12V to the thermostat, let alone the fan. So I temped the fan directly to 12V and it works. I traced the wire back to that taped bundle and decided not to proceed at that point. It will be arainy day project.

 

[Wayne County Hose]

Please, please, tell me that is not factory.

 

[KentT]

I've had to replace the fan on my 425, due to getting a stick in it. So far, I've had no "electrical gremlins" that have been associated with the wiring harness itself. I suspect my ignition switch is getting worn, though, because it sometimes will not make contact to engage the starter... everything comes on, but the starter solenoid doesn't engage. Wiggling the key usually takes care of it...

I need to put some graphite or something in the switch and see if that helps, but I keep forgetting it.

 

[Marks481]

Please, please, tell me that is not factory.

unfortunately, it probably is. My wiring harness doesn't have any devil clips in it, but it doesn't really appear that any real planning went into wire routing in the engine compartment, and no wire bundling/protection was installed. There are a couple fuses installed inline in wires; no central fuse block/terminal block was used.

Definitely an area where much improvements could be made; however there really isn't much in the way of wiring in the PT to begin with.

 

[ponytug]

Dear Ken,

I don't know if this helps, but I blew mine out with compressed air, added DOxit contact cleaner, cycled the key, and blew it out again. I assume that the CRC DW cleaner would work well, but I have used the CAIG products for years at work to good effect.

Long run, I want to replace the switch with a waterproof marine switch and some relays, since all of this started when the switch got some overspray from cleaning up.

All the best,

Peter

I've had to replace the fan on my 425, due to getting a stick in it. So far, I've had no "electrical gremlins" that have been associated with the wiring harness itself. I suspect my ignition switch is getting worn, though, because it sometimes will not make contact to engage the starter... everything comes on, but the starter solenoid doesn't engage. Wiggling the key usually takes care of it...

I need to put some graphite or something in the switch and see if that helps, but I keep forgetting it.

 

[BobRip]

Please, please, tell me that is not factory.

Yep it's a factory devil clip. Not really too bad to replaced, once you know where it is at.

 

[ldabe]

As the old saying goes (well, not that old) "Been there, done that."

Bob Rip, I had to do the same thing. Only, it probably took me longer than you to find that bugger (oophs! Satan snap). The hardest part is getting your hand in there to get to it.

Also, when I put the connector from harness to engine back together, one prong did not line up correctly...but made just enough connection to make a 'bad connection'.

It would start (the PT) but then 5, 15, maybe even 20 minutes later it would just die. That connector was the problem. Once I straitened the blade back, to fit right I didn't have any problem.

That is...after I took apart quite a few "grounds" to clean and make sure they were tight...because that is what I thought the problem was.

 

[BobRip]

As the old saying goes (well, not that old) "Been there, done that."

Bob Rip, I had to do the same thing. Only, it probably took me longer than you to find that bugger (oophs! Satan snap). The hardest part is getting your hand in there to get to it.

Also, when I put the connector from harness to engine back together, one prong did not line up correctly...but made just enough connection to make a 'bad connection'.

It would start (the PT) but then 5, 15, maybe even 20 minutes later it would just die. That connector was the problem. Once I straitened the blade back, to fit right I didn't have any problem.

That is...after I took apart quite a few "grounds" to clean and make sure they were tight...because that is what I thought the problem was.

I actually ended up replacing the wire between the fan and the thermal switch (there was nothing wrong with it) because I traced the wrong wire from the thermal switch. For some reason PT had the fuse on the wire to the fan. I assumed that this wire was to the power and misdiagnosed the problem. So I spent most of the day on this problem (I am embarassed to say). I of all people should know better.