water temperature gauge goes to red; using a temperature gun reading of top of radiator was 150F, top water hose at 140F coolant not hot, gauge red

lake side bob said: part number from the parts book for the machine is 9Y33655 the new number is 1265869. Click to expand... 1265869 is the listed replacement for 9Y3365, which in turn replaced 9Y3088. So all good there. lake side bob said: I used a meat thermometer to test the water 50/50 mix in the radiator it read 174. I take it the new regulator never got hot enough to open? Click to expand... I would agree. The fact that the radiator got to 174 would indicate that coolant is passing through the bypass line in the cooling system that allows a certain amount of flow through the radiator even when the regulator is completely closed. See the attachment, top of Page 4. You really need to work the machine hard to get the regulator to open fully.

Nige said: 1265869 is the listed replacement for 9Y3365, which in turn replaced 9Y3088. So all good there. I would agree. The fact that the radiator got to 174 would indicate that coolant is passing through the bypass line in the cooling system that allows a certain amount of flow through the radiator even when the regulator is completely closed. See the attachment, top of Page 4. You really need to work the machine hard to get the regulator to open fully. Click to expand... Today Friday, we dug a hole with the excavator through tough hardpan. The machine warmed up a bit for 10 mins first then worked it for ½ hour. I took temp reading before digging; coolant 174F, top radiator 170F, top hose 155F, lower hose 110F, metal elbow sender screws into 180F, temp sender 176F. Temp gauge in dash went into the red zone. I took temp reading after digging the hole; coolant 172F, top radiator 172F, top hose 159F, did not check lower hose, metal elbow sender screws into 180F, temp sender 180 then went down to 168F. Next we tightened the belts, water pump which was a little loose and fan. Next dug another hole. The results were: coolant 172F, top radiator 170F, top hose 147F, metal elbow 175F, temp sender 147F. The temp gauge in the cab was on the line between green and red. This is not normal; the temp gauge should be some distance from the red zone. Do you think the temp gauge in the dash is not reading correctly? Can that happen? The wiring tests are correct; wire off the sender and wire grounded tests. With the water pump belt tension tighten; I was hoping that was the problem but not so. Yes the coolant temp did not get to 180F, but the temp gauge in the dash went to the red zone. Any comments, suggestions? I am stumped.

Looking back I don’t think you ever posted a photo of the gauge in the dash. That would be handy, along with an indication of the needle position when you did the tests above.

lake side bob said: Today Friday, we dug a hole with the excavator through tough hardpan. The machine warmed up a bit for 10 mins first then worked it for ½ hour. I took temp reading before digging; coolant 174F, top radiator 170F, top hose 155F, lower hose 110F, metal elbow sender screws into 180F, temp sender 176F. Temp gauge in dash went into the red zone. I took temp reading after digging the hole; coolant 172F, top radiator 172F, top hose 159F, did not check lower hose, metal elbow sender screws into 180F, temp sender 180 then went down to 168F. Next we tightened the belts, water pump which was a little loose and fan. Next dug another hole. The results were: coolant 172F, top radiator 170F, top hose 147F, metal elbow 175F, temp sender 147F. The temp gauge in the cab was on the line between green and red. This is not normal; the temp gauge should be some distance from the red zone. Do you think the temp gauge in the dash is not reading correctly? Can that happen? The wiring tests are correct; wire off the sender and wire grounded tests. With the water pump belt tension tighten; I was hoping that was the problem but not so. Yes the coolant temp did not get to 180F, but the temp gauge in the dash went to the red zone. Any comments, suggestions? I am stumped. Click to expand... Its a possibility that you have two Different sensor readings. One sensor might be reading the actual water temp at the radiator, and the other, a critical engine temperature warning. That why you may be getting a warming light on the dash. It means to shut down immediately.

Kool J said: Its a possibility that you have two Different sensor readings. One sensor might be reading the actual water temp at the radiator, and the other, a critical engine temperature warning. That why you may be getting a warming light on the dash. It means to shut down immediately. Click to expand... You dont have to take my word on it, but as an experienced heavy equipment operator for 40 years. Who can repair any equipment i operate, I always got the issues corrected myself in quick time and back to work without having to call a mechanic. I love my job as an operator bro and take seriously with pride.

Kool J said: Its a possibility that you have two Different sensor readings. One sensor might be reading the actual water temp at the radiator, and the other, a critical engine temperature warning. That why you may be getting a warming light on the dash. It means to shut down immediately. Click to expand... That's exactly what the machine has. See the snip from the electrical schematic below The signal from the "water temperature unit" (aka coolant temp sender) is what powers the temp gauge on the panel. The "water temperature switch" activates at a set temperature and illuminates a warning light on the dash panel for high coolant temperature. At the same time it sounds a warning buzzer. The specifications for the 8T-9793 normally-closed Switch are as follows. Contacts close at 107.2±2.8°C (225±5°F) with rising temperature. Contacts close at a minimum of 93°C (199.4°F) with falling temperature. As I understand it the OP is concerned about high coolant temp readings on the gauge. I do not recall him ever mentioning anything regarding the high coolant temp warning light/buzzer.

Nige said: That's exactly what the machine has. See the snip from the electrical schematic below The signal from the "water temperature unit" (aka coolant temp sender) is what powers the temp gauge on the panel. The "water temperature switch" activates at a set temperature and illuminates a warning light on the dash panel for high coolant temperature. At the same time it sounds a warning buzzer. The specifications for the 8T-9793 normally-closed Switch are as follows. Contacts close at 107.2±2.8°C (225±5°F) with rising temperature. Contacts close at a minimum of 93°C (199.4°F) with falling temperature. As I understand it the OP is concerned about high coolant temp readings on the gauge. I do not recall him ever mentioning anything regarding the high coolant temp warning light/buzzer. View attachment 364703 Click to expand... Yes the reason I am looking into this is that the warning buzzer went off while digging a pond the operator does not remember if a warning light came on. I did a ohm test on the new sender it read 300 cold. I am trying to figure out what the two electric wires coming out of the housing right next to the temp sender. Is this the "water temperature switch"? The blue connector is not metric size it is a little loose on the new temp sender. I will get a photo of the water temp gauge in the dash went it is hot.

Nige said: The specifications for the 8T-9793 normally-closed Switch are as follows. Contacts close at 107.2±2.8°C (225±5°F) with rising temperature. Click to expand... Correction. That should read “contacts OPEN at 107.2±2.8°C (225±5°F) with rising temperature”

lake side bob said: Yes the reason I am looking into this is that the warning buzzer went off while digging a pond the operator does not remember if a warning light came on. Click to expand... The warning buzzer can go off for a number of reasons, not just high coolant temperature. How can he be sure what it went off for.?

lake side bob said: I am trying to figure out what the two electric wires coming out of the housing right next to the temp sender. Is this the "water temperature switch"? Click to expand... It is. With the key ON unplug the 2-pin connector to the left of the switch and check what happens in the cab in the way of warning lights and/or buzzer. Do you have a manual for this machine and do you know what all the various warning lights are for.?

The connector on single wire sensor looks wrong never saw one like that always a eyelet and a nut

I’ve seen this type before. The connection on the end of the sender looks a bit like a smaller version of the top end of a spark plug.

Nige said: It is. With the key ON unplug the 2-pin connector to the left of the switch and check what happens in the cab in the way of warning lights and/or buzzer. Do you have a manual for this machine and do you know what all the various warning lights are for.? Click to expand... Have the maintenance and parts manuals

lake side bob said: Have the maintenance and parts manuals Click to expand... Noticed that when the machine key is turned to auxiliary, not engine started, the water temp gauge moves about 1/4 through the green zone the hydraulic temp gauge does not move. Might be a bad gauge in the dash.

And it appears the yellow wire is cut (to the left of plug)on the 2 wire switch/sensor

bobatack said: And it appears the yellow wire is cut (to the left of plug)on the 2 wire switch/sensor Click to expand... No the yellow wire comes out of the back plastic loom it just appears to end (cut off)

Took three photos of the water temp gauge in the dash. one finger in photo is the engine stopped and cold two fingers is the key turned to only auxiliary three fingers is the engine just started I think the problem is the water temp gauge in the dash, the needle for some reason has moved to the right so when engine is up to operating temp it is in the red zone of the in between green red zone.

lake side bob said: I think the problem is the water temp gauge in the dash, the needle for some reason has moved to the right so when engine is up to operating temp it is in the red zone of the in between green red zone. Click to expand... You could be correct, but your comment below from an earlier post may be relevant and should be investigated further. Reduced conductivity at that terminal due to a "loose connection" could well be affecting the gauge reading. lake side bob said: The blue connector is not metric size it is a little loose on the new temp sender. Click to expand...

Well it appears the problem was the water temp gauge in the cab dash. I replaced it, and the needle is not going into the red zone stays in the middle of the green zone. The old one a mechanic noticed was not going to the peg on the left side when engine turned off; was about 3/16 to the right, so when the engine temp was warmed up it would be at the junction of the green and red color area on the dial. All that work just to fine out it was the temp gauge in the dash. Thank you every one for your reply and many suggestions. This forum site is wonderful.

Thanks for the follow-up. This site is truly great, and it's members are very helpful.