YM1700 Temp light coming on

[puresol]

Ok I installed the new temp and oil switch. No leaks at the oil switch. No leaks at the temp switch. I flushed the radiator, no chemicals just plain water. I flushed the block, no chemicals just straight water. Refilled the cooling system with 25/75 mix. The overflow tank I installed seems to be working. Engine heats up coolant goes into overflow tank, engine cools down coolant is drawn out of the overflow tank. Nothing is coming out of the overflow hose. Upper and lower radiator hoses are new. Radiator cap is new. No sign of steam there. Coolant is not spewing from the tractor. I can even find a leak. But after about 10-15 minutes the temp light comes on. I also sprayed the radiator out, through the fins, as best possible. Any ideas?

 

[kenmac]

could be crud rust etc in the block restricting flow/circulation.I don't use tap water. only distilled. do you know if the temp sending unit is correct ?

 

[puresol]

I assume its correct. I ordered it from Hoye for a YM1700. It did not look exactly the same, but my new alternator didnt look exactly the same either. So looks can be deceiving. I just ran it about ten minutes with the rotary mower attached and cut a little grass. The temp light never came on!? But the oil pressure light began to flicker. So I shut it down.

 

[puresol]

Ok went back outside re-installed the oil pressure gauge i fought to remove. Funny how that works. Started the tractor and it showed 70 at first then backed off to 50. The needle did jump a little, but never under 50 and never over 70. Is it possible I have damage in my harness that is making my switches short out.

 

[winston1]

If you reinstall the pressure sending switch, watch the light, if it flickers remove the wire from the sender, use an ohm meter from sender to ground. If you don't get a reading your sender is bad. If you do get a reading your wiring is bad.

In your case I would either invest in a temperature gauge or one of these. Non-Contact Infrared Laser Thermometer They were $19 the other day. Inflation You can use the ohm meter on this sender also. Readings will be opposite. If you get a reading it is telling you the engine is hot. No reading tells you all is cool.

In your case right now a boil over is about all you can trust.

 

[NickBlade]

Ok went back outside re-installed the oil pressure gauge i fought to remove. Funny how that works. Started the tractor and it showed 70 at first then backed off to 50. The needle did jump a little, but never under 50 and never over 70. Is it possible I have damage in my harness that is making my switches short out.

YES - I had similar problems on with my F22D; temp gauge working sporadically and warning lights not working properly. I finally pulled the cluster to check bulbs and found what looked like the results of a rodent that nested in the cluster. After eight separate repairs of opens and shorts, lots of things are working better now. If your cluster is as easy to pull as mine, it is well worth the effort.

Here's a couple pics of things that were "ratted out". :laughing:

 

[puresol]

I had originally wanted to put gauges in. Then I changed my mind and figured I would try to work with the indicator lights. I ordered new bulbs, new temp and oil switches. I took apart the light cluster and cleaned it up. Got all of the sockets working and tested each one. They all worked. I installed and hooked up the new switches. Should be good as new, right? Nope. My oil pressure light would flicker, come on sometimes, doesnt really act right. I have no confidence in it. I took the oil switch out and put the gauge that was in the tractor when I got the tractor back in. Gauge reads 60psi, fluctuates some, but generally the needle sits about 60psi. So maybe at least I have a temp indicator I can trust. Nope. The temp light comes on sometimes and sometimes it doesnt. I can idle the tractor 5 minutes at 1500 rpm the light will come on. I let the tractor cool down to the point I can safely remove the radiator cap, the light is still ON. I worked with the tractor on Saturday, just goofing around, observing the tractor, checking for leaks. The tractor is still new to me, I recognize its thirty plus years old, and I new I would have some work to do. The temp light never came on after dragging a plow for approx 1 hour. Shut the tractor down for about three hours. Came home, hooked up the rotary cutter, cut for 15min temp light came on. Once again let the tractor cool down, but the temp light is still on. Eventually it goes off, but by that time I can touch the motor. I by-passed the wiring harness with a new wire and the same thing continues to happen. I will get an ohm meter and follow Winston advice above, or I may just ditch the warning light gizmo's and put in gauges.

 

[kenmac]

If the motor is cool to the touch. Maybe bad temp switch. Like has been said , you can test it with a meter. Ny light has only come on a couple times when radiator got stopped up with grass seed. I have no idea as to what the setting ( to have the light come on) is

 

[NickBlade]

I took apart the light cluster and cleaned it up... I by-passed the wiring harness with a new wire and the same thing continues to happen. I will get an ohm meter and follow Winston advice above, or I may just ditch the warning light gizmo's and put in gauges.

Looks like you are certain the cluster is good. Running the separate wire from the sending unit was a good idea, but I don't think that you bypassed the entire wiring harness, just the leg between the bulb and ground (the sending unit grounds to complete the circuit and energize the bulb). You may indeed have an intermittent wiring fault from the battery to the bulb. It is much less likely, though, becuase problems between the voltage supply and the bulb (both a short and an open) always prevent the bulb from lighting (keeps it off). Only problems between the bulb and the sending unit can turn the bulb on (short). You might check on that, but if you completely replaced the path from bulb to sending unit, that was probably the only wiring test you needed for your symptoms, as long as you *removed* the existing wiring harness between the bulb and the sender.

So it may be the sending unit. But didn't you say it was new? I trust what Winston says )), but be careful using an ohm meter to test while experiencing the problem. Remember to turn the key OFF if you measure anything OTHER than the sending unit to ground. Measuring resistance with voltage on the leads can damage the meter. At the very least, it will give you false readings becuase the meter applies it's own voltage to test for resistance. Also, Winston's instructions didn't seem clear to me. (it's probably me )

So to be clear:

If you expect the sending unit to be turning the light ON, reading ohms between it and ground should be zero (or a very low number).
If you expect the sending unit to be keeping the light OFF, reading ohms between it and ground should be infinite (or a very high number).

If that's what you get, look for the problem somewhere else.
Anything else indicates a malfunctioning sending unit.

Good luck troubleshooting, or in installing the new gauge. :laughing:

 

[winston1]

No doubt my instructions aren't to clear. I did state to remove the wire from the sender before using the ohm meter. That will avoid damaging the meter. :thumbsup: