cyber3d Posted November 2, 2010 Report Share Posted November 2, 2010 Need some advice here on temp sensors. What the heck is going on with my spa? Symptoms: The temperature on the display rapidly changes showing 99, 105, 102, 104,..etc. The pump and heater clicking on and off rapidly. No error code appears OHM tests: The high temp cutoff sensor reads on my multi-meter (at 82 degrees) 21900 OHMs (should be about 26500 OHMs) The temperature sensor reads on my multi-meter (at 82 degrees) 27600 OHMs (should be about 26500 OHMs) Spa Model: Sundance Marin circa. 1994 Sentry 800 system Quote Link to comment Share on other sites More sharing options...
wuice Posted November 3, 2010 Report Share Posted November 3, 2010 Need some advice here on temp sensors. What the heck is going on with my spa? Symptoms: The temperature on the display rapidly changes showing 99, 105, 102, 104,..etc. The pump and heater clicking on and off rapidly. No error code appears OHM tests: The high temp cutoff sensor reads on my multi-meter (at 82 degrees) 21900 OHMs (should be about 26500 OHMs) The temperature sensor reads on my multi-meter (at 82 degrees) 27600 OHMs (should be about 26500 OHMs) Spa Model: Sundance Marin circa. 1994 Sentry 800 system Always turn power off before touching anything If the display is misreporting the temperature, replace the temp sensor. They are cheap and can fail. That said, it should create an error code, commonly "watchdog" (the ---- on the display). We have a little test plug that mimics all the sensors to eliminate them as a source problem. The range on the hilimit sensor seems low, but i personally rarely see those fail and should create a OH error message With the age I would also look closely for a loose connection, they can cause some very funny behavior. Double and triple check the wires in the sensor harness (making sure they are seated completely) and confirm it's plugged in fully. The next check would be the transformer plugs (back then it should have two separate plugs) They are white plugs, one with blue/yellow wires, and the other with a red and black. If you unplug them and look in from the business end you will notice a metal "sleeve", ive seen a few cases where the sleeve has opened up through the years and makes a poor connection. If the "sleeves" look more like a C than an O (sounds a little confusing but would make sense looking at it) a small flat head screwdriver can be used to reform them into an O. After all that we would start to suspect the board, i have seen on more than one occasion, but due to the cost lets hope not. Keep me updated attached is an image for reference to those plugs, this should be very close to your board Quote Link to comment Share on other sites More sharing options...
cyber3d Posted November 6, 2010 Author Report Share Posted November 6, 2010 Hey Wuice, thanks for the reply. At the moment I have on order a replacement temp sensor and high-limit sensor. At $30 each, it was not too bad and I'll give it a try. I have checked all the relevant connections and in fact replaced the transformer and ozonator earlier this month. With all the pushin' and pullin' of wires, hoses, and whatnot, we'll see soon enough if it is some loose connection somewhere. I'll keep posting with my findings. Quote Link to comment Share on other sites More sharing options...
thecanuck22 Posted December 30, 2010 Report Share Posted December 30, 2010 Quote"We have a little test plug that mimics all the sensors to eliminate them as a source problem. " would love to get one of those or the instructions on how to make one? please. Quote Link to comment Share on other sites More sharing options...
david_bilton Posted January 6, 2011 Report Share Posted January 6, 2011 Quote"We have a little test plug that mimics all the sensors to eliminate them as a source problem. " would love to get one of those or the instructions on how to make one? please. Jacuzzi/sundance spa tech's get these when they complete the course Quote Link to comment Share on other sites More sharing options...
david_bilton Posted January 6, 2011 Report Share Posted January 6, 2011 Need some advice here on temp sensors. What the heck is going on with my spa? Symptoms: The temperature on the display rapidly changes showing 99, 105, 102, 104,..etc. The pump and heater clicking on and off rapidly. No error code appears OHM tests: The high temp cutoff sensor reads on my multi-meter (at 82 degrees) 21900 OHMs (should be about 26500 OHMs) The temperature sensor reads on my multi-meter (at 82 degrees) 27600 OHMs (should be about 26500 OHMs) Spa Model: Sundance Marin circa. 1994 Sentry 800 system Always turn power off before touching anything If the display is misreporting the temperature, replace the temp sensor. They are cheap and can fail. That said, it should create an error code, commonly "watchdog" (the ---- on the display). We have a little test plug that mimics all the sensors to eliminate them as a source problem. The range on the hilimit sensor seems low, but i personally rarely see those fail and should create a OH error message With the age I would also look closely for a loose connection, they can cause some very funny behavior. Double and triple check the wires in the sensor harness (making sure they are seated completely) and confirm it's plugged in fully. The next check would be the transformer plugs (back then it should have two separate plugs) They are white plugs, one with blue/yellow wires, and the other with a red and black. If you unplug them and look in from the business end you will notice a metal "sleeve", ive seen a few cases where the sleeve has opened up through the years and makes a poor connection. If the "sleeves" look more like a C than an O (sounds a little confusing but would make sense looking at it) a small flat head screwdriver can be used to reform them into an O. After all that we would start to suspect the board, i have seen on more than one occasion, but due to the cost lets hope not. Keep me updated attached is an image for reference to those plugs, this should be very close to your board also check the capacitors if they look swollen then the board is toast aswell as check the black connector on the board that the wire harness attaches to if it is loose the board is toast good luck Quote Link to comment Share on other sites More sharing options...
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