Engine temp sensor troubleshoot
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=39557
Printed Date: October-07-2024 at 6:31am
Topic: Engine temp sensor troubleshoot
Posted By: Dreaming
Subject: Engine temp sensor troubleshoot
Date Posted: August-01-2016 at 4:49pm
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After swapping out the Protec ignition and TBI, I was able to start my boat yesterday. I did have the engine started prior to the swap, but that was 3 years ago, so my memory of what was working is really foggy. over all, it seems like I got things connected correctly, but the Temp gauge Is pegged hot. I am not sure how the circuit works to begin my trouble shooting... Does power go from the key to the gauge? I am assuming that the temp sensor is a thermistor and provides a variable resistance to the ground? or should I be getting power at the sensor on top of the engine, and a ground at the gauge? |
Replies:
Posted By: Jonny Quest
Date Posted: August-01-2016 at 5:35pm
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Typically, a "pegged" gauge is a sign of bad or faulty wiring. When you did the ProTech swap out, the temperature gauge wiring should not have been touched. You likely did remove the high temperature switch wiring that would have been connected to control module that puts the engine into "limp home" mode. That's what is hooked-up to the red light in the middle of your dash board. One way to be sure, is to change-out the impeller. Not a big job and they are not expensive. Just ensure that you don't re-install the pump backwards. (The voice of experience here...) Then you can run an I/R or laser temperature reader and see what your heads, block and manifolds are doing. That will let you know if your gauge is bad (once it's properly wired-up). JQ ------------- Current 2003 Ski Nautique 206 Limited Previous 2001 Ski Nautique Open Bow 1994 Ski Nautique Open Bow Aqua skiing, ergo sum |
Posted By: Dreaming
Date Posted: August-01-2016 at 7:54pm
| The impeller is new, and I could hold my hand on the manifold while running on the hose, so I suspect temps are all good, but wanted to fix the temp gauge so I am not in a sticky situation once I get on the water (hopefully this week) I'll take a look at the wiring harness at the engine... IIRC I did not touch or clip the tan wire that the temp sensor is attached to, it is possible that the issue is at the dash/gauge as well. I may have to pop up under the dash and see what I am getting on the VOM. it would be nice to know the resistance of the sensor if someone has that though. |
Posted By: desertskier
Date Posted: August-01-2016 at 8:19pm
| I have never checked one personally but others have said the range of the sensor is 30 to 240 Ohms. |
Posted By: KENO
Date Posted: August-01-2016 at 10:50pm
Just to add a little here the higher the resistance , the lower the temp indication so the 30 ohms would correspond to the high end of your meter say 240 degrees. And 240 ohms would correspond to the low end of your meter say 120 degrees. So if you ground it, it will be pegged high, disconnect it, it should read pegged low. The 30 ohms =240 degrees and 240 ohms =120 degrees examples I gave are for a teleflex temp meter I have but the principal of low resistance giving a high temp and high resistance giving a low temp should apply for any temp meters we use. If you take the wire off of your sending unit and turn the key to RUN the meter should go from your pegged high indication to pegged low unless the wiring to the meter is grounded somewhere or the meter is bad. To verify this, I just went out and grounded my sending unit to the engine with the key in RUN and temp pegged high. Removed the jumper and it went to the low end. Hope this is understandable and it helps KenO |
desertskier wrote:Posted By: Dreaming
Date Posted: August-02-2016 at 2:33pm
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Cool, thanks for the temp/Ohms conversion. I went out to look at the boat for 2 seconds last night, as I was flying solo with the kids for the evening, and discovered that the gauge is pegged when the ignition is off also... I assume this means I have a gauge that needs to be replaced. I looked at Nautique parts, and found nothing... are these unobtainium? |
Posted By: Dreaming
Date Posted: August-02-2016 at 2:42pm
Apparently the NP site search doesn't work well.... here is the temp guage I believe I have, google search brought it up.  http://www.nautiqueparts.com/enginetemperaturegaugeteleflex.aspx" rel="nofollow - teleflex temp gauge |
Posted By: JayG80
Date Posted: August-04-2016 at 12:47pm
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http://www.jamestowndistributors.com/userportal/document.do?docId=842&title=Troubleshooting+Teleflex+Water+Temperature+Gauges" rel="nofollow - Trouble Shoot Teleflex Water Temp Gauge ------------- 2007 Ski 2002 Ski |