PT1850 Hydraulic Oil Cooler Fan

BWSwamper · May 16, 2018

Greetings All,

Just purchased a used PT1850. The unit came with no manuals, but I ordered one from PT. However, the manual doesn't include a wiring diagram.

Could someone explain the fan set up to me. It looks like the cooling fan is wired into a solenoid with wires heading back toward the dash. I was guessing there was a temp sensor based auto kick in and a manual overide switch on the dash. Any help appreciated before I start digging.

I see there is a thermal relay for the cooler.

I have only operated the machine to off-load the machine at delivery and a bit around the yard and then into the shed. The fan has not kicked in and the dash fan switch doesn't cause the fan to come on.

Checked the fan operation already using the supply to the flashing light. Fan seems to work fine.

woodlandfarms · May 16, 2018

Welcome to the club. there are a few of us here with 1850's Happy to help out.

First thing is that you should let us know the year and take a few pictures of the beast. The machines change subtly and it leads to some confusion for sure. I don't believe the two of us who have 1850s have a dash switch for the fan. Ours are on relays. the relays are located on the passenger side of the engine tub, toward he back on the "frame rail" there should be an aluminum block with hoses running into it and a thermostat on the outside with a couple of electical wires. I have enclosed a couple wiring diagram. take it with a grain of salt. Its a good starting point but not the be all end all

I have also included (and i forget who did this) a wiring diagram should you ever decide to redo your wiring from ground up. Its a better design IMO and something to work off of should you get bored..

Oh and if you have to replace the fan, the factory version for mine machine is SPAL 30100385

BWSwamper · May 17, 2018

Thanks for the diagrams. That will certainly get me on my way.

I got the machine through an auction. It is a 2007 model. I haven't taken any pictures yet, but the auction site still has several photos up, so here is a link.

Used Construction, Agricultural Equip., Trucks, Trailers & more

Comparing this machine to the manufactuer's website pictures, it looks like the previous owner used the "rear lights" switch and converted it to a manual fan circuit. They also appear to have rotated the seat leveling switch to left right...if that is indeed the original position.

I spoke with the PowerTrac factory and they confirmed that this machine did not come with a manual fan switch. So, now I've got to sort out what has been done. At present the manual fan switch doesn't cause the fan to engage. When I checked the fan with another power source it ran fine. The thermal relay for the fan seems to still be in place. I'll spend some time with the diagrams and report back.

One question. How long does the machine typically operate before the thermal relay kicks the fan in? I need to be sure the thermal relay is functioning.

Also, forgot to mention the battery is draining down. It had to be jumped to load and unload. I thought it was a bad battery, but when I replaced it with a new battery it drained down overnight. Perhaps something to do with the wiring modification.

Does your hour meter stay on even when the machine is shut off?

ponytug · May 17, 2018

The hour meter should not run with the machine off. That suggests that you have a +12V leak, possibly through the "added" fan switch.
The thermal "switches" are button disk switches. They are, in my opinion, under rated for the load, but they are cheap. A hot air source (hair dryer, heat gun) should cause it to complete the circuit. I'm not sure what yours should be set for.

All the best, Peter

woodlandfarms · May 17, 2018

My meter stayed on with the switch engine off but switch on. You got that for 6K? SCORE!!!!!! It is very similar to mine and Kens.. You have a new series engine but that doesnt mean much.

Usually the fan is on in 10 minutes of mowing on a warm day. I put a streamer in the fan so I can see it running. I have used it in the winter with no implement and it never came on. But it is a weak link and as it has been possible hard wired there is more than likely an issue.

Notes, your tires are not slope rated. They look like 12 ply tires and not balloon so your slope work will probably be limited to 35 degrees or so before you start sliding sideways. You will NOT tip over, but make sure you have a solution at the bottom of your hill before you start side mowing. I personally think you got a great deal. It looks reasonably clean for such high hours. You will find this group super helpful, everyone here has been beyond graciious in teaching me online mechanics and hydraulics. as well as Terry (you should talk with Terry in Tazwell). They are crap at emails but great at phone callls.

BWSwamper · May 17, 2018

Thanks for all the info.

I thought the tires didn't look quite right. Is there a good aftermarket source for the correct balloon tires?

woodlandfarms · May 18, 2018

Tires are a difficult subject on the 1850. While I have a few 45 degree slopes I don't go near them even though I guess I can. Scared I won't get back out without my buddies dozer. 4 ply tires are the softest and at 6PSI provide a lot of grip. I though work a lot in recently cut timber so I tend to be in areas with sharp branches that will puncture a 4 ply. I have 6 ply and honestly next time around will get 8 ply. The tires you have look tobe off of skid steers and not much is going to mess them up.

If it were me, I would get a sense of the machine first before I would buy any tires. Not sure how steep your land is but 45 degrees is crazy steep. You will have to scramble up the hill on all fours if you stall out.

I think Carlisle 4 ply ags are what comes with. I am in Toronto working so the link I am providing is for Canada.

26x12-12 4ply CARLISLE TRU POWER 178lb - Specialty Tire

BWSwamper · May 18, 2018

Thanks.

This machine is bound for the family home place in the southern Appalachian mountains of N.E. Georgia. The bottom pastures are tractorable with standard ag tractors, but the hillside pastures are dicey. We got a wheel in the air twice with a friend's 4x4 60 HP New Holland last fall while building fences in a hillside pasture. That's when I decided to try to track down one of the PT1850s.

A nearby neighbor died in a tractor roll-over when I was in highschool. He was trying to go a "little further" up the hillside. That got my attention. I've always been sensitive to the issue and always use ROPS and seatbelts - unlike some acquaintances, unfortunately.

The good news is that most of the hillside pastures at our location do taper off to moderate slopes (naturally, or due to man-made terraces) before dropping into a gorge or such. So, I do think I can probe the limits of the current tires without much risk.

I have often wondered why "Alpine" tractors so common in Europe don't seem to be present in the Mountainous areas of the U.S. The Swiss and German ones are technically available in the U.S. but with outrageously high prices. I would have thought one of the big manufacturers would have seen an opportunity to offer at least a few models.

I did see an Alpine-ized Kubota M7040 on the internet - but, that apparently was done by a European distributor. Didn't catch all the details as my German isn't that good.

MossRoad · May 18, 2018

Nice find! Welcome to TBN and the Power Trac forum! :thumbsup:

SpringHollow · May 18, 2018

extremely nice deal - congratulations. The disk thermostats fail fairly easily. I have bypassed it when it failed until i could get a replacement.

Ken